Method and apparatus for accelerated link setup

ABSTRACT

A method for performing active scanning by a non-AP STA may comprise transmitting, to a group of APs, one or more probe request frames and receiving in response, configuration chance count (CCC) values from first and second APs of the group of APs. The CCC values may be integer values that represent configuration instances of the respective APs. The CCC values may be stored in a memory of the non-AP STA. A determination may be made, based on the information stored in the memory, as to which AP is preferred. An association procedure may be performed with the preferred AP. Other disclosed methods employ passive scanning.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/362,305 filed on Nov. 28, 2016, which is a continuation of U.S.patent application Ser. No. 14/942,127 filed on Nov. 16, 2015, whichissued on Nov. 29, 2016 as U.S. Pat. No. 9,510,375, which claims thebenefit of U.S. patent application Ser. No. 13/738,589 filed on Jan. 10,2013, which issued on Dec. 1, 2015 as U.S. Pat. No. 9,204,473, whichclaims the benefit of U.S. Provisional Application Ser. No. 61/585,420filed on Jan. 11, 2012 and U.S. Provisional Application Ser. No.61/719,663 filed on Oct. 29, 2012, the contents of which are herebyincorporated by reference.

BACKGROUND

A link setup procedure may be configured in an Institute of Electricaland Electronics Engineers (IEEE) 802.11 communications system to includea number of phases. An example link setup process may include an accesspoint (AP) discovery phase, a network discovery phase, an additionaltime sync function (TSF) phase, an authentication and association phase,and a higher layer internet protocol (IP) setup phase. Such a link setupprocedure may take up to a few seconds or more to complete.

SUMMARY

A method and apparatus may be configured to perform accelerated linksetup. A method may include a station (STA) acquiring information aboutan AP of an IEEE 802.11 network in advance through a previouslyconnected IEEE 802.11 interface and/or an interface other than the IEEE802.11 network. The STA may use the acquired information during a linksetup procedure between the STA and the AP. The information may includea suggestion for a specific procedure to complete the link setupprocedure between the STA and the AP.

A method and apparatus may be used to pre-establish a securityassociation between a STA and a network to enable and optimize discoveryof another network. For example, a fast-EAP may be encapsulated into an802.11 frame, such as, for example, an authentication frame or anassociation frame. The authentication procedure performed on the newnetwork may be non-EAP based.

An apparatus may transmit a request for network discovery informationfrom a network entity and receive network discovery information inresponse. The network discovery information may be received over acellular network, for example, a 3GPP network. The network discoveryinformation may be received via a Layer 2 protocol.

An apparatus may transmit a request to obtain an IP addressconfiguration from a network. For example, the apparatus may request andreceive an IP address configuration during an EAP authentication processor during a non-EAP authentication process. The IP address configurationmay be received over a cellular network, for example, a 3GPP network.

A method for performing active scanning by a non-AP STA may comprisetransmitting, to a group of APs, one or more probe request frames andreceiving in response, configuration chance count (CCC) values fromfirst and second APs of the group of APs. The CCC values may be integervalues that represent configuration instances of the respective APs. TheCCC values may be stored in a memory of the non-AP STA. A determinationmay be made, based on the information stored in the memory, as to whichAP is preferred. An association procedure may be performed with thepreferred AP. Other disclosed methods employ passive scanning.

BRIEF DESCRIPTION OF THE DRAWINGS

A more detailed understanding may be had from the following description,given by way of example in conjunction with the accompanying drawingswherein:

FIG. 1A is a system diagram of an example communications system in whichone or more disclosed embodiments may be implemented;

FIG. 1B is a system diagram of an example wireless transmit/receive unit(WTRU) that may be used within the communications system illustrated inFIG. 1A;

FIG. 1C is a system diagram of an example radio access network and anexample core network that may be used within the communications systemillustrated in FIG. 1A;

FIG. 2A is a diagram of an example IEEE 802.11 setup procedure;

FIG. 2B is a continuation of the example IEEE 802.11 setup procedureshown in FIG. 2A;

FIG. 3 is a flow chart of a baseline procedure for accelerated linksetup (ALS) using pre-acquired information;

FIG. 4 is a diagram of an example short beacon frame supportingaccelerated link setup (ALS);

FIG. 5 is a diagram of an example modification to a primary beacon framesupporting ALS;

FIG. 6 is a diagram of an example fast initial link setup (FILS)management action frame;

FIG. 7 is a diagram of an example of an optimized access point (AP)discovery procedure initiated by a STA based on pre-acquired knowledge;

FIG. 8 is a diagram of an example of an optimized AP discovery procedureinitiated by an AP based on pre-acquired information;

FIG. 9 is a diagram of an example method in which an authentication,authorization, and accounting (AAA) server may integrate IdentityProvider (OP) and enhanced access network discovery and selectionfunction (eANDSF) functionalities to enable seamless authentication andfast link setup;

FIG. 10 is a diagram of another example method in which anauthentication, authorization and accounting (AAA) server may integrateOP and enhanced access network discovery and selection function (eANDSF)functionalities to enable seamless authentication and fast link setup;

FIG. 11 is a diagram of an example method in which an AAA server mayintegrate OP functionality to enable seamless authentication and fastlink setup;

FIG. 12 is a diagram of another example method in which an AAA servermay integrate OP functionality to enable seamless authentication andfast link setup;

FIG. 13 is a diagram of an example method for a pre-established securityassociation between a STA and a network to enable seamlessauthentication and fast initial link setup;

FIG. 14 is a diagram of another example method for a pre-establishedsecurity association between a STA and a network to enable seamlessauthentication and fast initial link setup;

FIG. 15 is a diagram of another example method for a pre-establishedsecurity association between a STA and a network to enable seamlessauthentication and fast initial link setup;

FIG. 16 is a diagram of an example method for supporting the use ofpre-defined system parameter sets;

FIG. 17 is a diagram of another example method for supporting the use ofpre-defined system parameter sets;

FIG. 18 is a diagram of another example method for supporting the use ofpre-defined system parameter sets;

FIG. 19 is a diagram of an example method where a STA may receiveconfiguration instance identifier information without full configurationinstance information;

FIG. 20 is a diagram of an example method where a STA may includeconfiguration instance identifier information for pre-acquired systemconfigurations;

FIG. 21 is a diagram of an example method for performing fast link setupwith location-based pre-acquired knowledge; and

FIG. 22 is a diagram of an example method for link setup optimization.

DETAILED DESCRIPTION

FIG. 1A is a diagram of an example communications system 100 in whichone or more disclosed embodiments may be implemented. The communicationssystem 100 may be a multiple access system that provides content, suchas voice, data, video, messaging, broadcast, etc., to multiple wirelessusers. The communications system 100 may enable multiple wireless usersto access such content through the sharing of system resources,including wireless bandwidth. For example, the communications systems100 may employ one or more channel access methods, such as code divisionmultiple access (CDMA), time division multiple access (TDMA), frequencydivision multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrierFDMA (SC-FDMA), and the like.

As shown in FIG. 1A, the communications system 100 may include wirelesstransmit/receive units (WTRUs) 102 a, 102 b, 102 c, 102 d, a radioaccess network (RAN) 104, a core network 106, a public switchedtelephone network (PSTN) 108, the Internet 110, and other networks 112,though it will be appreciated that the disclosed embodiments contemplateany number of WTRUs, base stations, networks, and/or network elements.Each of the WTRUs 102 a, 102 b, 102 c, 102 d may be any type of deviceconfigured to operate and/or communicate in a wireless environment. Byway of example, the WTRUs 102 a, 102 b, 102 c, 102 d may be configuredto transmit and/or receive wireless signals and may include userequipment (UE), a mobile station, a fixed or mobile subscriber unit, apager, a cellular telephone, a personal digital assistant (PDA), asmartphone, a laptop, a netbook, a personal computer, a wireless sensor,consumer electronics, a station (STA) in an IEEE 802.11 network, and thelike.

The communications systems 100 may also include a base station 114 a anda base station 114 b. Each of the base stations 114 a, 114 b may be anytype of device configured to wirelessly interface with at least one ofthe WTRUs 102 a, 102 b, 102 c, 102 d to facilitate access to one or morecommunication networks, such as the core network 106, the Internet 110,and/or the networks 112. By way of example, the base stations 114 a, 114b may be a base transceiver station (BTS), a Node-B, an eNode B, a HomeNode B, a Home eNode B, a site controller, an access point (AP), awireless router, and the like. While the base stations 114 a, 114 b areeach depicted as a single element, it will be appreciated that the basestations 114 a, 114 b may include any number of interconnected basestations and/or network elements.

The base station 114 a may be part of the RAN 104, which may alsoinclude other base stations and/or network elements (not shown), such asa base station controller (BSC), a radio network controller (RNC), relaynodes, etc. The base station 114 a and/or the base station 114 b may beconfigured to transmit and/or receive wireless signals within aparticular geographic region, which may be referred to as a cell (notshown). The cell may further be divided into cell sectors. For example,the cell associated with the base station 114 a may be divided intothree sectors. Thus, in one embodiment, the base station 114 a mayinclude three transceivers, i.e., one for each sector of the cell. Inanother embodiment, the base station 114 a may employ multiple-inputmultiple output (MIMO) technology and, therefore, may utilize multipletransceivers for each sector of the cell.

The base stations 114 a, 114 b may communicate with one or more of theWTRUs 102 a, 102 b, 102 c, 102 d over an air interface 116, which may beany suitable wireless communication link (e.g., radio frequency (RF),microwave, infrared (IR), ultraviolet (UV), visible light, etc.). Theair interface 116 may be established using any suitable radio accesstechnology (RAT).

More specifically, as noted above, the communications system 100 may bea multiple access system and may employ one or more channel accessschemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. Forexample, the base station 114 a in the RAN 104 and the WTRUs 102 a, 102b, 102 c may implement a radio technology such as Universal MobileTelecommunications System (UMTS) Terrestrial Radio Access (UTRA), whichmay establish the air interface 116 using wideband CDMA (WCDMA). WCDMAmay include communication protocols such as High-Speed Packet Access(HSPA) and/or Evolved HSPA (HSPA+). HSPA may include High-Speed DownlinkPacket Access (HSDPA) and/or High-Speed Uplink Packet Access (HSUPA).

In another embodiment, the base station 114 a and the WTRUs 102 a, 102b, 102 c may implement a radio technology such as Evolved UMTSTerrestrial Radio Access (E-UTRA), which may establish the air interface116 using Long Term Evolution (LTE) and/or LTE-Advanced (LTE-A).

In other embodiments, the base station 114 a and the WTRUs 102 a, 102 b,102 c may implement radio technologies such as IEEE 802.16 (i.e.,Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000,CDMA2000 1×, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), InterimStandard 95 (IS-95), Interim Standard 856 (IS-856), Global System forMobile communications (GSM), Enhanced Data rates for GSM Evolution(EDGE), GSM EDGE (GERAN), and the like.

The base station 114 b in FIG. 1A may be a wireless router, Home Node B,Home eNode B, or access point, for example, and may utilize any suitableRAT for facilitating wireless connectivity in a localized area, such asa place of business, a home, a vehicle, a campus, and the like. In oneembodiment, the base station 114 b and the WTRUs 102 c, 102 d mayimplement a radio technology such as IEEE 802.11 to establish a wirelesslocal area network (WLAN). In another embodiment, the base station 114 band the WTRUs 102 c, 102 d may implement a radio technology such as IEEE802.15 to establish a wireless personal area network (WPAN). In yetanother embodiment, the base station 114 b and the WTRUs 102 c, 102 dmay utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE,LTE-A, etc.) to establish a picocell or femtocell. As shown in FIG. 1A,the base station 114 b may have a direct connection to the Internet 110.Thus, the base station 114 b may not be required to access the Internet110 via the core network 106.

The RAN 104 may be in communication with the core network 106, which maybe any type of network configured to provide voice, data, applications,and/or voice over internet protocol (VoIP) services to one or more ofthe WTRUs 102 a, 102 b, 102 c, 102 d. For example, the core network 106may provide call control, billing services, mobile location-basedservices, pre-paid calling, Internet connectivity, video distribution,etc., and/or perform high-level security functions, such as userauthentication. Although not shown in FIG. 1A, it will be appreciatedthat the RAN 104 and/or the core network 106 may be in direct orindirect communication with other RANs that employ the same RAT as theRAN 104 or a different RAT. For example, in addition to being connectedto the RAN 104, which may be utilizing an E-UTRA radio technology, thecore network 106 may also be in communication with another RAN (notshown) employing a GSM radio technology.

The core network 106 may also serve as a gateway for the WTRUs 102 a,102 b, 102 c, 102 d to access the PSTN 108, the Internet 110, and/orother networks 112. The PSTN 108 may include circuit-switched telephonenetworks that provide plain old telephone service (POTS). The Internet110 may include a global system of interconnected computer networks anddevices that use common communication protocols, such as thetransmission control protocol (TCP), user datagram protocol (UDP) andthe internet protocol (IP) in the TCP/IP internet protocol suite. Thenetworks 112 may include wired or wireless communications networks ownedand/or operated by other service providers. For example, the networks112 may include another core network connected to one or more RANs,which may employ the same RAT as the RAN 104 or a different RAT.

Some or all of the WTRUs 102 a, 102 b, 102 c, 102 d in thecommunications system 100 may include multi-mode capabilities, i.e., theWTRUs 102 a, 102 b, 102 c, 102 d may include multiple transceivers forcommunicating with different wireless networks over different wirelesslinks. For example, the WTRU 102 c shown in FIG. 1A may be configured tocommunicate with the base station 114 a, which may employ acellular-based radio technology, and with the base station 114 b, whichmay employ an IEEE 802 radio technology. A WTRU may be referred to as astation (STA) or a non-access point (non-AP) STA.

FIG. 1B is a system diagram of an example WTRU 102. As shown in FIG. 1B,the WTRU 102 may include a processor 118, a transceiver 120, atransmit/receive element 122, a speaker/microphone 124, a keypad 126, adisplay/touchpad 128, non-removable memory 106, removable memory 132, apower source 134, a global positioning system (GPS) chipset 136, andother peripherals 138. It will be appreciated that the WTRU 102 mayinclude any sub-combination of the foregoing elements while remainingconsistent with an embodiment.

The processor 118 may be a general purpose processor, a special purposeprocessor, a conventional processor, a digital signal processor (DSP), aplurality of microprocessors, one or more microprocessors in associationwith a DSP core, a controller, a microcontroller, Application SpecificIntegrated Circuits (ASICs), Field Programmable Gate Array (FPGAs)circuits, any other type of integrated circuit (IC), a state machine,and the like. The processor 118 may perform signal coding, dataprocessing, power control, input/output processing, and/or any otherfunctionality that enables the WTRU 102 to operate in a wirelessenvironment. The processor 118 may be coupled to the transceiver 120,which may be coupled to the transmit/receive element 122. While FIG. 1Bdepicts the processor 118 and the transceiver 120 as separatecomponents, it will be appreciated that the processor 118 and thetransceiver 120 may be integrated together in an electronic package orchip.

The transmit/receive element 122 may be configured to transmit signalsto, or receive signals from, a base station (e.g., the base station 114a) over the air interface 116. For example, in one embodiment, thetransmit/receive element 122 may be an antenna configured to transmitand/or receive RF signals. In another embodiment, the transmit/receiveelement 122 may be an emitter/detector configured to transmit and/orreceive IR, UV, or visible light signals, for example. In yet anotherembodiment, the transmit/receive element 122 may be configured totransmit and receive both RF and light signals. It will be appreciatedthat the transmit/receive element 122 may be configured to transmitand/or receive any combination of wireless signals.

In addition, although the transmit/receive element 122 is depicted inFIG. 1B as a single element, the WTRU 102 may include any number oftransmit/receive elements 122. More specifically, the WTRU 102 mayemploy MIMO technology. Thus, in one embodiment, the WTRU 102 mayinclude two or more transmit/receive elements 122 (e.g., multipleantennas) for transmitting and receiving wireless signals over the airinterface 116.

The transceiver 120 may be configured to modulate the signals that areto be transmitted by the transmit/receive element 122 and to demodulatethe signals that are received by the transmit/receive element 122. Asnoted above, the WTRU 102 may have multi-mode capabilities. Thus, thetransceiver 120 may include multiple transceivers for enabling the WTRU102 to communicate via multiple RATs, such as UTRA and IEEE 802.11, forexample.

The processor 118 of the WTRU 102 may be coupled to, and may receiveuser input data from, the speaker/microphone 124, the keypad 126, and/orthe display/touchpad 128 (e.g., a liquid crystal display (LCD) displayunit or organic light-emitting diode (OLED) display unit). The processor118 may also output user data to the speaker/microphone 124, the keypad126, and/or the display/touchpad 128. In addition, the processor 118 mayaccess information from, and store data in, any type of suitable memory,such as the non-removable memory 106 and/or the removable memory 132.The non-removable memory 106 may include random-access memory (RAM),read-only memory (ROM), a hard disk, or any other type of memory storagedevice. The removable memory 132 may include a subscriber identitymodule (SIM) card, a memory stick, a secure digital (SD) memory card,and the like. In other embodiments, the processor 118 may accessinformation from, and store data in, memory that is not physicallylocated on the WTRU 102, such as on a server or a home computer (notshown).

The processor 118 may receive power from the power source 134, and maybe configured to distribute and/or control the power to the othercomponents in the WTRU 102. The power source 134 may be any suitabledevice for powering the WTRU 102. For example, the power source 134 mayinclude one or more dry cell batteries (e.g., nickel-cadmium (NiCd),nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion),etc.), solar cells, fuel cells, and the like.

The processor 118 may also be coupled to the GPS chipset 136, which maybe configured to provide location information (e.g., longitude andlatitude) regarding the current location of the WTRU 102. In additionto, or in lieu of, the information from the GPS chipset 136, the WTRU102 may receive location information over the air interface 116 from abase station (e.g., base stations 114 a, 114 b) and/or determine itslocation based on the timing of the signals being received from two ormore nearby base stations. It will be appreciated that the WTRU 102 mayacquire location information by way of any suitablelocation-determination method while remaining consistent with anembodiment.

The processor 118 may further be coupled to other peripherals 138, whichmay include one or more software and/or hardware modules that provideadditional features, functionality and/or wired or wirelessconnectivity. For example, the peripherals 138 may include anaccelerometer, an e-compass, a satellite transceiver, a digital camera(for photographs or video), a universal serial bus (USB) port, avibration device, a television transceiver, a hands free headset, aBluetooth® module, a frequency modulated (FM) radio unit, a digitalmusic player, a media player, a video game player module, an Internetbrowser, and the like.

FIG. 1C is an example system diagram of the RAN 104 and the core network106. As noted above, the RAN 104 may employ an E-UTRA radio technologyto communicate with the WTRUs 102 a, 102 b, 102 c over the air interface116. The RAN 104 may also be in communication with the core network 106.

The RAN 104 may include eNode-Bs 140 a, 140 b, 140 c, though it will beappreciated that the RAN 104 may include any number of eNode-Bs whileremaining consistent with an embodiment. The eNode-Bs 140 a, 140 b, 140c may each include one or more transceivers for communicating with theWTRUs 102 a, 102 b, 102 c over the air interface 116. In one embodiment,the eNode-Bs 140 a, 140 b, 140 c may implement MIMO technology. Thus,the eNode-B 140 a, for example, may use multiple antennas to transmitwireless signals to, and receive wireless signals from, the WTRU 102 a.

Each of the eNode-Bs 140 a, 140 b, 140 c may be associated with aparticular cell (not shown) and may be configured to handle radioresource management decisions, handover decisions, scheduling of usersin the uplink and/or downlink, and the like. As shown in FIG. 1C, theeNode-Bs 140 a, 140 b, 140 c may communicate with one another over an X2interface.

The core network 106 shown in FIG. 1C may include a mobility managementgateway (MME) 142, a serving gateway 144, and a packet data network(PDN) gateway 146. While each of the foregoing elements are depicted aspart of the core network 106, it will be appreciated that any one ofthese elements may be owned and/or operated by an entity other than thecore network operator.

The MME 142 may be connected to each of the eNode-Bs 142 a, 142 b, 142 cin the RAN 104 via an S1 interface and may serve as a control node. Forexample, the MME 142 may be responsible for authenticating users of theWTRUs 102 a, 102 b, 102 c, bearer activation/deactivation, selecting aparticular serving gateway during an initial attach of the WTRUs 102 a,102 b, 102 c, and the like. The MME 142 may also provide a control planefunction for switching between the RAN 104 and other RANs (not shown)that employ other radio technologies, such as GSM or WCDMA.

The serving gateway 144 may be connected to each of the eNode Bs 140 a,140 b, 140 c in the RAN 104 via the S1 interface. The serving gateway144 may generally route and forward user data packets to/from the WTRUs102 a, 102 b, 102 c. The serving gateway 144 may also perform otherfunctions, such as anchoring user planes during inter-eNode B handovers,triggering paging when downlink data is available for the WTRUs 102 a,102 b, 102 c, managing and storing contexts of the WTRUs 102 a, 102 b,102 c, and the like.

The serving gateway 144 may also be connected to the PDN gateway 146,which may provide the WTRUs 102 a, 102 b, 102 c with access topacket-switched networks, such as the Internet 110, to facilitatecommunications between the WTRUs 102 a, 102 b, 102 c and IP-enableddevices. An access router (AR) 150 of a wireless local area network(WLAN) 155 may be in communication with the Internet 110. The AR 150 mayfacilitate communications between APs 160 a, 160 b, and 160 c. The APs160 a, 160 b, and 160 c may be in communication with STAs 170 a, 170 b,and 170 c.

The core network 106 may facilitate communications with other networks.For example, the core network 106 may provide the WTRUs 102 a, 102 b,102 c with access to circuit-switched networks, such as the PSTN 108, tofacilitate communications between the WTRUs 102 a, 102 b, 102 c andtraditional land-line communications devices. For example, the corenetwork 106 may include, or may communicate with, an IP gateway (e.g.,an IP multimedia subsystem (IMS) server) that serves as an interfacebetween the core network 106 and the PSTN 108. In addition, the corenetwork 106 may provide the WTRUs 102 a, 102 b, 102 c with access to thenetworks 112, which may include other wired or wireless networks thatare owned and/or operated by other service providers.

FIGS. 2A and 2B are diagrams of an example IEEE 802.11 link setupprocedure where the 802.11i/Extensible Authentication Protocol (EAP) maybe used. This example procedure 200 may include an AP discovery phase201, a network discovery phase 202, an additional time sync function(TSF) phase 203, an authentication phase 204, an association phase 205,a security setup phase 206, and an IP setup phase 207. A wirelesscommunication system may include one or more stations (STA)s 208, one ormore APs 209 a, 209 b, 209 c, and one or more network elements 209 d. ASTA 208 may include a wireless transmit receive unit (WTRU) or a non-APSTA, and a network element 209 d may include, for example, a router, ahome agent (HA), an authentication, authorization, and accounting (AAA)server, an authentication server (AS), or a remote authenticationdial-in user service (RADIUS).

In the AP discovery phase 201, the STA 208 may use active or passivescanning to find APs in range. In an active scanning example, the STA208 may transmit respective probe request frames 211 a, 211 b, 211 c toAP1 209 a, AP2 209 b, and APn 209 c. In response, each AP may transmit arespective probe response frame 212 a, 212 b, 212 c to the STA 208. In apassive scanning example, the STA 208 may wait to receive respectivebeacons 210 a, 210 b, 210 c from AP1 209 a, AP2 209 b, and APn 209 cprior to performing a probe request/response frame exchange.

In the network discovery phase 202, the STA 208 may search for theproper service provider network by transmitting a guarded action system(GAS) initial request frame 213 a to, for example, AP1 209 a. Inresponse, AP1 209 a may transmit a query request 213 b to networkelement 209 d, and receive a query response 213 c. In response toreceiving the query response 213 c, AP1 209 a may transmit a GAS initialresponse frame 213 d to STA 208. The STA 208 may transmit a GAS comebackrequest frame 213 e to AP1 209 a and receive a GAS comeback requestframe 213 f in response. If necessary, one or more GAS comebackrequest/response exchanges 213 g may be performed, for example, if theGAS response is too large to fit into one MAC management protocol dataunit (MMPDU) and GAS fragmentation is used for delivery.

An additional TSF phase 203 may be performed. During the TSF phase 203,STA 208 may transmit a probe request frame 214 a to, for example, AP1209 a, and receive a probe response frame 214 b in response. Theadditional TSF phase may be used to further synchronize the timesynchronization timers between, for example, AP1 209 a and STA 208. Thesynchronization may be performed by using a timestamp field in the proberesponse frame 214 b.

An authentication phase 204 may be performed. During the authenticationphase 204, STA 208 may transmit an authentication request frame 215 ato, for example, AP1 209 a, and receive an authentication response frame215 b in response.

An association phase 205 may be performed. During the association phase205, STA 208 may transmit an association request frame 216 a to, forexample, AP1 209 a, and receive an association response frame 216 b inresponse.

A security setup phase 206 may be performed. STA 208 may initiate thesecurity setup phase 206 by transmitting an extensible authenticationprotocol (EAP) over local area network (LAN) (EAPOL) start frame 217 ato, for example, AP1 209 a. AP1 209 a may transmit an EAP request frame217 b to STA 208. The EAP request frame 217 b may include a field thatindicates an identity of AP1 209 a. The STA 208 may transmit an EAPresponse frame 217 c to AP1 209 a in response. The EAP response frame217 c may include a field that indicates an identity of STA 208. AP1 209a may transmit a request frame 217 d to a network element 209 d using anAAA protocol, for example. The request frame 217 d may include a fieldthat indicates an identity of the STA 208.

The network element 209 d may transmit a challenge/transport layeredsecurity (TLS) start frame to AP1 209 a in response. AP1 209 a maytransmit an EAP request/TLS start frame 217 f to STA 208. In response,STA 208 may transmit an EAP response/TLS client hello frame 217 g to AP1209 a. AP1 209 a may transmit a request/pass through frame 217 h tonetwork element 209 d, and receive a challenge/server certificate frame217 i in response. AP1 209 a may transmit an EAP request/pass throughframe 217 j to STA 208, and receive an EAP response/client certificateframe 217 k in response.

AP1 209 a may transmit a request/pass through frame 2171 to the networkelement 209 d, and receive a challenge/encryption type frame 217 m inresponse. AP1 209 a may transmit an EAP request/pass through frame 217 nto STA 208, and receive an EAP response frame 217 o in response. AP1 209a may transmit a request frame 217 p to network element 209 d, andreceive an accept frame 217 q in response. AP1 209 a may transmit an EAPsuccess frame 217 r to STA 208. In response to the EAP success frame 217r, STA 208 and AP1 209 a may perform a 4-way handshake 217 s.

An IP setup phase 207 may be performed to obtain an IP addressassignment. For example, STA 208 may transmit a dynamic hostconfiguration protocol (DHCP) discovery frame 218 a to, for example, AP1209 a. AP1 209 a may transmit a DHCP discovery frame 218 b to networkelement 209 d, and receive a DHCP offer frame 218 c in response. AP1 209a may transmit a DHCP offer frame 218 d to STA 208. STA 208 may transmita DHCP request frame 218 e to AP1 209 a. AP1 209 a may transmit a DHCPrequest frame 218 f to network element 209 d, and receive a DHCPacknowledgement (ACK) 218 g in response. AP1 209 a may transmit a DHCPACK 218 h to STA 208.

Other EAP methods that provide mutual authentication, for example,EAP-Subscriber Identity Module (EAP-SIM), EAP-Authentication and KeyAgreement (AKA) and EAP-Tunneled Transport Layer Security (EAP-TTLS) mayalso be used.

Some issues have been encountered with 802.11 initial link setupprocedures, such as the example protocol illustrated in FIG. 2. Oneissue may include the length of time, for example, up to several secondsor more, required for the 802.11 network to establish an initialconnection with a STA. Another issue may be that when a user of a STA isinvolved in an interactive session, for example, a Skype video, aconnection may not be able to be maintained when the STA switches fromanother network to an 802.11 network, for example, from a ThirdGeneration Partnership Project (3GPP) network to wireless local areanetwork (WLAN). Another issue may be that IEEE 802.11 networks may berequired to support a large number of users simultaneously entering anextended service set (ESS) and securely provide them withauthentication.

Some goals for 802.11 networks may be set with respect to initial linkset up time, minimum user load and robustness in the presence of highbackground load. With respect to initial link set up time, one examplegoal may be for the initial link set up time for IEEE 802.11 networks tobe less than 100 ms while maintaining a Robust Security NetworkAssociation (RSNA) security level where the initial link setup time maybe the amount of time required to gain the ability to send internetprotocol (IP) traffic with a valid IP address through the AR Withrespect to minimum user load, an example goal may be for IEEE 802.11networks to support at least 100 non-AP STAs entering an ESS within onesecond and to successfully conduct link setup. With respect torobustness in the presence of a high background load, an example goalmay be to provide a link setup for media loads of at least fiftypercent.

Example methods to reduce the initial link setup time for 802.11networks are summarized in Table 1. These examples, however, may not besufficient to meet the 100 ms link setup time goal because, even usingaggressive predictions, the possible achievement time for link setupusing passive scanning is 90 ms, even without considering the networkdiscovery phase. A realistic time consumption may be significantlylonger in real networks where a large number of APs may be present.Further, the IEEE 802.11 link setup protocol illustrated in FIG. 2 isvery long and will not satisfy the initial link setup time requirements.

TABLE 1 Higher AP Discovery Layer Active Passive Network AdditionalAuth. & (DHCP/ Phase scanning scanning Discovery TSF Assoc. IP) # of 1+,STA- 1.5, STA- 2+, STA- 1, STA- 7~13, 2, STA- message AP AP AP AP STA-APAP rounds Per AP Per AP 1, AP-AS 4+, AP- 2, AP- per per Per AP RADIUSDHCP Channel channel server Time Mean: Mean: 5 ms to 2 ms to 15 ms to 2s ~100 ms (Today) 102 ms for 1100 ms 30 ms per 5 ms 2.4 GHz: for AP n/afor 5.8 2.4 GHz:; Multiple Extensible Authentication Protocol Worst 2300ms AP: n/a Generalized Pre-Shared Key (EAP- case: for GPSK) @ OFDM6: 6ms + 71 ms 680 ms 5.8 GHz; processing time, where OFDM6 Worst may be amode in 802.11PHY with case: a minimum data rate of 6 Mbps 3400 msPossible 2 ms 50 ms Optimizations EAP-GPSK w/ Piggyback@ achievement(possible for OFDM6: (with at 5 GHz) large 5 ms + 35 ms processing timeknowledge) number of (reduced number of messages users require lessprocessing time, simultaneously further optimization might be entering apossible) network

Referring to Table 1, time values shown in the “possible achievement”row may be based on, for example, 802.11ai.

Although the 802.11 Authentication Phase may be removed when RSNA isused, the Authentication Phase may nevertheless be performed to aid inbackward compatibility. The IP address assignment may be combined intoearlier Phases of the link setup process in 802.11ai.

Example Internet Engineering Task Force (IETF) procedures may includeDHCP with rapid commit to optimize IP Assignment Phase, which is a fastIP Assignment scheme. Configuration change counts (CCC)s orconfiguration sequence numbers may be used for the GAS configurationand/or AP configuration to optimize the system information communicationbetween the STA and the AP/Network.

802.11ai procedures may not be sufficient to achieve the requirements ofan initial link setup time of less than 100 ms. This may be because thecurrent “possible” achievement time for link setup using passivescanning is 90 ms, even without considering the network discovery phase.In addition, the numbers given in the “possible achievement” row arevery aggressive, for example, 2 ms for active scanning. A realistic timeconsumption may be significantly longer in real networks where there maybe a large number of APs present. Some or all phases in the link setupprocess may be initiated by the STA. The AP may respond to a STArequest, and may not have a mechanism to enable the AP to initiate anoptimization in the link setup process. Most of the phases in thecurrent 802.11 link setup process may be further optimized for fasterlink setup time while maintaining an RSNA level of security.

The current initial link setup process is very long and may not satisfythe initial link setup time requirements. Accommodation of a largenumber of users simultaneously entering the ESS may not be possiblewithin the link setup time frames that have been identified. A methodand apparatus that optimizes the link setup process using a dynamic,flexible, and interoperable procedure is needed.

The link setup process in 802.11 may not allow optimization of theprocess that includes the elimination of some steps or phases at the AP.For example, in 802.11, all phases in the link setup process may beinitiated by STA as shown in FIG. 2A.

The system configuration may be defined. For example, the configurationchange count or configuration sequence number may be defined. Further,in IEEE 802.11 an example initial setup procedure such as the protocolillustrated in FIG. 2A and FIG. 2B, all phases in the link setup processmay be initiated by the STA. The AP only responds to a STA request, and,therefore, may not have a mechanism to initiate optimizations in thelink setup process. Further yet, accommodation of a large number ofusers simultaneously entering the ESS may not be possible within thelink setup time frames that have been identified, for example, 100 ms.

In addition to the above, with the increasing demand for mobility, andincreased availability of multimode devices with multiple wirelessinterfaces, for example, 3GPP and IEEE 802.11, seamless handover andservice continuity across these networks may become a differentiatingservice for an operator to offer to its users. Secure access proceduresto 802.1x/EAP WLAN networks may suffer from lack of automation,significant added latency, non-seamless handoff, and disruption ofpreviously established services over cellular networks, for example,voice over internet protocol (VoIP) sessions as a result of a handoffthat often require user interaction, pre-provisioning devices, and WLANnetworks with credentials.

One or more embodiments disclosed herein may speed up initial link setupfor 802.11 devices by using information that the AP and/or STApre-acquires. APs and/or STAs may pre-acquire certain information abouteach other. For example, a STA may switch from its previous connection,such as a 3G network, to a WLAN network, or from one AP to another AP inan ESS. In this example, it may be possible for a suitable or preferredWLAN AP to pre-acquire certain information about the candidate STA. Itmay also be possible for a STA to pre-acquire knowledge about apreferred AP based on, for example, geography locations and networkaccess history, including but not limited to frequently visited places,daily routines, etc.

With an AP and/or STA pre-acquiring such information, it may be possibleto skip and/or combine certain phases in the link setup procedure. Inaddition, depending on what and how much information an AP and/or STAhas pre-acquired, various optimizations may be applied to a link setupprocedure to reduce the link setup time. Such a shortened or optimizedprocedure may also be initiated by the AP.

FIG. 3 is a flow chart of a baseline procedure for accelerated linksetup using pre-acquired information. A wireless communication systemmay include one or more stations STAs 301, one or more APs 302 a, 302 b,302 c, and one or more network elements 302 d. A STA 301 may include awireless transmit receive unit (WTRU), and a network element 302 d mayinclude, for example, a router, a home agent (HA), an AAA server, an AS,or a RADIUS.

In the example procedure 300 illustrated in FIG. 3, an APn 302 c mayinitiate link setup optimizations by using pre-acquired informationabout a STA 301. Further, the example procedure illustrated in FIG. 3may accommodate multiple variants of accelerated link setup proceduresin a dynamic, flexible, and interoperable manner while maintainingbackward compatibility.

With respect to the link setup procedure illustrated in FIG. 2, thebaseline procedure for accelerated link setup (ALS) using pre-acquiredinformation illustrated in FIG. 3 may be driven by entities other thanthe STA 301. If no information on a STA or AP has been pre-acquired,then the ALS may function as an 802.11 link setup procedure thatincludes an AP discovery phase 303, a network discovery phase 304, anadditional TSF phase 305, an authentication phase 306, an associationphase 307, a security setup phase 308, an IP setup phase 309. If,however, the AP has performed a pre-acquired information phase 310 toobtain information about the STA 301 or vice versa, the STA 301 and APmay optimize the AP discovery phase 303 using the pre-acquiredinformation. In addition, the AP and STA may negotiate to skip orshorten the post-AP-discovery phases, for example, network discoveryphase 304, additional TSF phase 305, authentication phase 306,association phase 307, security setup phase 308, and IP setup phase 309,depending on the amount of the information that the STA and AP haveacquired with respect to each other.

For example, if a STA is conducting an interactive Skype call on a 3Gcellular network, the STA may switch to the WLAN network if it arrivesat a location where there are strong signals from a preferred AP. TheSTA and the preferred AP may pre-acquire information about each otherprior to link setup through the 3G network, such as security relatedparameters, available network services, etc. Given the pre-acquiredinformation, the STA may actively scan for only the preferred AP insteadof scanning for all available APs in the area, which may significantlyshorten the AP discovery process. Further, since the STA and AP may havealready pre-acquired security related parameters and available networkservices information, they may skip the network discovery phase 304,additional TSF phase 305 (since TSF may be conducted during the initialprobe request/probe response exchange) and the security setup phase 308,achieving even faster link setup, while maintaining the required RSNAlevel of security.

The example baseline procedure illustrated in FIG. 3 may include apre-acquiring information phase 310, an AP discovery phase 303 and apost-AP discovery phase 311. In the pre-acquiring information phase 310,APs and/or STAs may acquire knowledge about each other throughinterfaces other than the IEEE 802.11 air link directly between them.The pre-acquiring information phase 310 may not count as part of linksetup time and may be performed any time before the link setup betweenthe AP and the STA. The pre-acquiring information phase 310 may notnecessarily occur just prior to the link setup. In the AP discoveryphase 303, the STA 301 may find a proper AP with or without pre-acquiredinformation. If pre-acquired information is available, AP discovery maybe optimized accordingly and the specific procedure for the rest of thelink setup process may be communicated and negotiated between the AP andSTA. Otherwise, the AP discovery procedure 303 and the rest of the linksetup phases may be used to maintain backward compatibility. The post-APdiscovery phase 311 may include all remaining phases for setup of IPconnectivity between the STA and the AP, such as network discovery 304,additional TSF 305, authentication 306, association 307, security setup308, and IP setup 309. The Post-AP discovery phase 311 may be flexiblystructured such that none of its phases are mandatory. In order toaccelerate the link setup process, each of the phases may be skipped oroptimized depending on the availability and the amount of theinformation pre-acquired about the STA and the AP. In addition, the ALSprocedure illustrated in FIG. 3 provides a framework for combined phasesor a newly defined procedure. The selection of a specific procedure fora link setup case may be communicated between the AP and the STA throughthe proposed signaling mechanisms at the completion of the AP discoverystep.

Referring to FIG. 3, STA 301 and AP1 302 a may pre-acquire informationin the pre-acquiring information phase 310. For example, if the STA 301is connected to a WLAN, AP1 may receive candidate STA information 312 afrom APn 302 c, and STA 301 may receive candidate AP information 313 afrom APn 302 c. In another example, if the STA is connected to acellular network, for example, a network element 302 d, AP1 302 a mayreceive candidate STA information 312 b from network element 302 d, andSTA 301 may receive candidate AP information 313 b from network element302 d.

The candidate STA information 312 a, 312 b may be pre-acquired knowledgeabout a candidate STA that, for example, AP1 302 a may communicate withat some point in the future. The candidate STA information 312 a, 312 bmay include, for example, the medium access control (MAC) address of thecandidate STA, a capability of the candidate STA, security information,and/or a service package. The candidate AP information 313 a, 313 b maybe pre-acquired knowledge about a candidate AP that STA 301 maycommunicate with at some point in the future. The candidate APinformation 313 a, 313 b may include, for example, a service setidentification (SSID), a basic service set identifier (BSSID), an APcapability, a physical (PHY) mode, one or more rates, securityinformation, access network services information, and any otherinformation that may be included in a beacon or probe response frame.The candidate STA information 312 a, 312 b and the candidate APinformation 313 a, 313 b may also include information shown in Table 2below.

An accelerated link setup (ALS) capability indicator may be used toindicate whether or not ALS is supported by STAs, including AP andnon-AP STAs. The ALS indicator may include, for example, bit flaginformation that may be encoded in an existing information field byusing a reserved bit. For example, the reserved bit may be thecapability information field of the beacon frame. The reserved bit mayalso be encoded in one or more information fields or informationelements (IE)s.

The AP and the STA may use the ALS capability indicator to inform eachother about their ALS capabilities so that an ALS procedure may betriggered effectively. At initial link setup, both the AP and the STAmay send ALS capability indicator information at their earliest possibleopportunity. For example, an AP may send an ALS capability indicator inbeacon frames and/or probe response frames while a STA may send an ALScapability indicator in probe request frames and/or othermanagement/control frames as an initial frame to the AP.

IEs may be used to aid ALS procedures, and may include, for example, anI-know-you IE, an I-know-you-response IE, a Need-more-info IE, and aNeed-more-info-response IE. These IEs may be included in managementframes and may be transmitted over the WLAN air link between two STAs,including AP and non-AP STAs.

The I-know-you IE may allow the AP and/or the STA to notify the other atan early stage of initial link setup that it has pre-acquiredinformation about the other. When an I-know-you IE is used by an AP, itmay be sent in a first unicast frame from the AP to the STA, forexample, a probe response or an authentication response, to notify theSTA what information the AP has already pre-acquired. This informationmay include, for example, that the AP may know the STA identity such asa 48-bit MAC address; the AP may know the service needs of the STA andthe ability of the AP to provide those services; that the AP and the STAshare a credential/key, etc., and/or what information is needed, forexample, the AP may need more information about the STA, such asconfirmation from the STA and/or knowledge of the STA regarding theshared keys, etc. When an I-know-you IE is used by the STA, it may betransmitted in a first message from the STA to the AP, notifying the APwhat information the STA has pre-acquired about the AP, for example,that the AP is the preferred AP of the STA; the STA has pre-acquired theMAC/PHY parameters of the AP; that the STA has a shared credential/keywith the AP, that the STA is providing the AP with information about theSTA and/or what information the STA still needs from the AP.

In addition, an I-know-you IE may also include a suggestion from itstransmitter regarding how to pursue the remaining link setup process.For example, the suggestion may include a specific procedure to completethe link setup process, and may be based on the pre-acquiredinformation.

An I-know-you-response IE may be a response to an I-know-you IE that mayrequire further information. Such a response may include one or moreconfirmations, additions, and/or corrections to the information itemslisted in a received I-know-you IE.

A Need-more-info IE may allow the AP and the STA to further exchangeinformation to aid ALS if messages with I-Know-You andI-Know-You-Response IEs do not complete the necessary informationcommunications. For example, to negotiate how to complete the link setupprocess, the AP and/or the STA may need another round of messageexchanges to reach an agreement. The Need-more-info-response IE may be aresponse to a Need-more-info IE or an I-know-you-response IE that mayrequest further information.

A beacon transmission protocol may be performed to reduce systemoverhead and aid fast initial link setup. For example, a short beaconmay be transmitted in addition to a regular beacon. Contents of theshort beacon may be minimized to reduce system overhead and carryessential information for fast initial link setup. In this example, ashort beacon may be transmitted as frequently as demanded by link setupdelay requirements and, as such, may replace the regular primary beaconin one or more consecutive beacon cycles, replace the regular primarybeacon in a periodic manner, or may be transmitted more frequently thanthe regular primary beacon. In addition, the short beacon contents maybe influenced by an AP aware mode where the AP may have advanceinformation about one or more STAs. A short beacon may includeinformation relevant to one or more of: AP discovery; network discovery;security, for example, authentication and association; higher layerprotocol to speed up the link setup process; I-know-you IE;I-know-you-response IE; Need-more-info IE; and/orNeed-more-info-response IE.

An example short beacon frame 400 supporting ALS is illustrated in FIG.4. For example, the short beacon frame 400 may include anoptimized/minimized header 410, a primary beacon related informationfield 420, an optimized/minimized subset of primary beacon content field430, an AP discovery information field 440, a network discoveryinformation field 450, a security related information field 460, ahigher layer protocol information field 470, and one or more optionalelements field 480. The AP discovery information field 440, networkdiscovery information field 450, security related information field 460,and/or higher layer protocol information field 470 may be included inthe short beacon frame 400 on an as needed basis.

In another example, a beacon frame may be modified to aid fast initiallink setup. For example, a primary beacon may be modified to allow it toinclude essential information for fast initial link setup. In thisexample, the beacon contents may be influenced by an AP aware mode wherethe AP may have advance information about one or more STAs. The beaconmay include information relevant to one or more of: AP discovery;network discovery; security, for example, authentication andassociation; higher layer protocol to speed up the link setup process;I-know-you IE; I-know-you-response IE; Need-more-info IE; and/orNeed-more-info-response IE.

An example modification to a primary beacon frame 500 supporting ALS isillustrated in FIG. 5. For example, the primary beacon frame 500 mayinclude a header 510, a primary beacon content field 520, a short beaconrelated information field 530, an AP discovery information field 540, anetwork discovery information field 550, a security related informationfield 560, a higher layer protocol information field 570, and/or one ormore optional elements field 580. The short beacon related informationfield 530, AP discovery information field 540, network discoveryinformation field 550, security related information field 560, and/orhigher layer protocol information field 570 may be included in theprimary beacon frame 500 on an as needed basis.

In addition, an ALS capability indicator may be included in the beaconframes, in both the short beacon and the modified primary beacon. TheALS capability indicator may be either encoded in the capabilityinformation field of the beacon frame by using a reserved bit or encodedin other information fields or information elements in the beaconframes.

IEEE 802.11 management frames that are typically used in link setup maybe modified to aid fast initial link setup (FILS). For example,association/re-association and probe request and response messages maybe modified to aid FILS by including information relevant to one or moreof AP discovery; network discovery; security, for example,authentication and association; higher layer protocol to speed up thelink setup process; I-know-you IE; I-know-you-response IE;Need-more-info IE; and/or Need-more-info-response IE.

An IEEE 802.11 measurement pilot frame to assist STAs with scanning maybe modified to aid FILS. The measurement pilot frame may be a publicaction frame that may include a subset of the information included in aprimary beacon and may be transmitted more often than the primarybeacon. For example, the measurement pilot may be modified to aid FILSby including information relevant to one or more of AP discovery;network discovery; security, for example, authentication andassociation; higher layer protocol to speed up the link setup process;I-know-you IE; I-know-you-response IE; Need-more-info IE; and/orNeed-more-info-response IE.

In addition, other IEEE 802.11u frames, such as generic advertisementservice (GAS) initial request/response and GAS comeback request/responseframes, may be modified to aid FILS by including information relevant toone or more of AP discovery; network discovery; security, for example,authentication and association; higher layer protocol to speed up thelink setup process; I-know-you IE; I-know-you-response IE;Need-more-info IE; and/or Need-more-info-response IE.

In another example, a management frame to aid FILS, referred to as aFILS management frame, may include information relevant to one or moreof AP discovery; network discovery; security, for example,authentication and association; higher layer protocol to speed up thelink setup process; I-know-you IE; I-know-you-response IE; and/orNeed-more-info IE. The FILS management frame may be defined andimplemented as a FILS management action frame with the action defined assupporting the FILS function. The FILS management action frame mayinclude one or more of the following modes: a regular mode that requiresan acknowledgement (ACK) response and a No ACK mode that will notrequire an ACK response from the receiver.

A FILS management action frame may be a public action frame. A FILSmanagement action frame may be used for an inter-Basic Service Set(inter-BSS) and AP information exchange with an unassociated-STA.Examples of such information exchange scenarios may include thetransmitting STA or AP and receiving STA or AP being associated withdifferent BSSs and one or both of the transmitting and receiving STAsnot being associated to a BSS. A FILS management action frame may alsohave a dual protected mode, which may be used for STA to STAcommunication.

An example FILS management action frame 600 is illustrated in FIG. 6.For example, the FILS management action frame 600 may include a categoryfield 610, an action field 620, an AP discovery information field 630, anetwork discovery information field 640, a security related informationfield 650, a higher layer protocol information field 660, and one ormore optional elements field 670. The category field 610 may indicate,for example, that the FILS management action frame is a public actionframe. The action field 620 may indicate a FILS action. The AP discoveryinformation field 630, network discovery information field 640, securityrelated information field 650, and/or higher layer protocol informationfield 660 may be included in the FILS management action frame on an asneeded basis.

A FILS management action frame may be transmitted by an AP and may betransmitted in a unicast or a broadcast mode. The AP may transmit theFILS management action frame as frequently as needed to supportefficient operation of FILS in the BSS/system.

In another example, a FILS management action function may be supportedby a FILS request frame and a FILS response/report frame. A devicetransmitting a FILS request frame may request information relevant toone or more of: AP discovery; network discovery; security, for example,authentication and association; higher layer protocol to speed up thelink setup process; I-know-you IE; I-know-you-response IE; and/orNeed-more-info IE. A device transmitting a FILS response/report framemay respond with or report information relevant to one or more of: APdiscovery; network discovery; security, for example, authentication andassociation; higher layer protocol to speed up the link setup process;I-know-you IE; I-know-you-response IE; Need-more-info IE; and/orNeed-more-info-response IE.

Information pre-acquired by an AP and/or a STA may be used toeffectively optimize AP discovery. For example, a STA may obtainpreferred AP information through multiple mechanisms, such as aconnection to a network before switching to a WLAN network, andmemorized historic data with APs and locations, etc. At a STA,pre-acquired information may be classified into two major types: airinterface MAC/PHY parameters, for example, those in beacon and/or proberesponse frames such as service set identification (SSID)/basic serviceset identification (BSSID), service offerings, capability, PHYparameters, supported rates, quality of service (QoS) capability, etc.,and security-related information, for example, robust security network(RSN) information, shared key/credential with expiration time and/orvalid authentication context with expiration time. A minimumpre-acquired information at the STA may include a MAC address of apreferred AP, for example, the BSSID. Other information items may beavailable and used in an incremental manner.

If the BSSID of the AP is the only information that a STA haspre-acquired with respect to the coverage area of the AP, the APdiscovery process may be optimized from at least two aspects. First, theSTA may transmit a unicast probe request frame (not wildcard). Second,the AP discovery process may be returned once the probe response frameis received confirming its preferred AP selection, without a need toscan all the available APs in the area. If the BSSID of the AP and anyother information items have been pre-acquired by the STA, furtheroptimizations may be applied to AP discovery.

FIG. 7 is a diagram illustrating an example AP discovery method 700 withpre-acquired knowledge of the AP. In this example, the AP 710 and/or theSTA 720 may have pre-acquired information from a previous connection toa network, for example 3G, other WLAN AP, etc. The pre-acquiredinformation may also be from the memory of the STA 720 and its currentlocation. Pre-acquired information may be obtained in a variety of ways.In one example, the AP 710 may receive a message that includes candidateSTA information 722 from a network element 725. In another example, theSTA 720 may receive a message that includes candidate AP information 726from the network element 725.

Referring to FIG. 7, the STA 720 may receive a beacon 730 from the AP710. The beacon 730 may include an ALS capability indicator. The STA maytransmit a unicast request frame 740 to the AP 710. The unicast requestframe 740 may be a probe request frame, and may include an I-Know-YouIE. The unicast request frame 740 may be a new MAC management frame or amodified 802.11 MAC management frame. The I-Know-You IE may include theinformation items about the knowledge of the STA regarding the AP toseek confirmations and/or corrections from the AP, and it may alsoinclude request indicators to ask for further information from the AP.

When the AP 710 receives such a request frame with an I-Know-You IE fromthe STA 720, the AP 710 may transmit a response frame 750 back to theSTA 720. The response frame 750 may include an I-Know-You-Response IEincluding further details regarding how to complete the link setupprocess. Another round of message exchanges may be used for the AP 710and the STA 720 to gain further information about each other and reachan agreement regarding how to complete the link setup procedure. Forexample, the STA 720 may transmit a need-more information request frame760, and receive an need-more information response frame 770 from the AP710 in response. When the AP discovery phase 775 is completed, the restof the link setup 780 may be performed.

In this example, the AP discovery phase 775 may be completed in one ortwo message rounds between the STA and the AP and take approximately 4ms to 10 ms to complete. Additionally, in such AP discovery phase 775,the pre-acquired knowledge may be applied to derive an optimized way tocomplete the rest of link setup functions by the AP 710 and the STA 720.

An AP may pre-acquire a candidate STA's knowledge through itsconnections to a network. The pre-acquired information about a STA mayinclude the MAC address of the STA; service requirements; securityrelated information, for example, shared key/credential with expirationtime; and/or valid authentication context with expiration time, etc.Similarly, a minimum pre-acquired knowledge that an AP may have about aSTA may include the MAC address of the STA. Other information items, forexample, a STA capability, one or more service requirements, securityinformation, etc., may be available and used in an incremental manner.

If an AP has pre-acquired knowledge about a STA, for example, either theMAC address of the STA only or its MAC address with additionalinformation items, the AP may initiate an ALS procedure after receivinga first frame from the STA including the MAC address of the STA.

FIG. 8 is a diagram illustrating an example of optimized AP discoverymethod 800 initiated by an AP 810 based on pre-acquired information.Pre-acquired information may be obtained in a variety or ways. Forexample, a network element 815 may transmit a message that includescandidate STA information 817 to the AP 810. In another example, thenetwork element 815 may transmit a message that includes candidate APinformation 819 to STA 820.

In the example illustrated in FIG. 8, when an AP 810 receives a firstframe 830, for example a probe request frame, from a STA 820 includingthe MAC address of the STA 820, if the AP 810 has pre-acquiredinformation about the STA 820, the AP 810 may transmit a response frame840, for example, a probe response frame. The response frame 840 mayinclude an I-Know-You IE that indicates that it may be the correct APfor the STA 820. The I-Know-You IE may be used to request furtherinformation from the STA 820. The first frame 830 and the response frame840 may each include an ALS capability indicator. When receiving such aresponse from the AP 810, the STA 820 may terminate the scanning processso that the time used for scanning may be significantly reduced. The AP810 and STA 820 may perform further information exchanges. For example,the STA 820 may transmit a frame 850 that includes more informationabout the STA. The frame 850 may include a suggestion for a link setupprocedure. In response, the AP 810 may transmit a frame 860 in response.The frame 860 may include a confirmation of the suggested link setupprocedure.

In addition, through a response of the STA 820 to an I-Know-You IE ofthe AP 810, and further information exchanges between the AP 810 and theSTA 820 if needed, the AP 810 and the STA 820 may reach an agreementregarding how to complete the link setup process in a time efficientmanner. For example, the AP 810 and STA 820 may agree to skip, optimize,or combine certain link setup phases. In this way, the AP 810 maysuccessfully apply its pre-acquired information to actively participatein determining how to optimize the link setup process.

Post-AP-discovery link setup optimizations may vary with the availableinformation that an AP and a STA may have pre-acquired prior to APdiscovery and during an AP discovery phase. Table 2 provides examplepost-AP-discovery link setup optimizations based on differentassumptions of pre-acquired knowledge.

TABLE 2 Phase Function Optimization Considerations Network Find a rightMay be skipped if the AP knows the Discovery service provider serviceneed of the STA and also network knows the connected network can providethe services Additional Further time May be skipped depending on the TSFsynchronization air link status; the AP may also with the inform the STAif it can be skipped selected AP 802.11 Verify the STA, may be skippedif RSNA is used Authentication but not useful for RSNA 802.11 Check RSNmay be combined into the last Association info provided message round inAP-discovery by the STA, phase; also assign may also be anotherstandalone association message round, but may be used identifier tocarry some information items (AID) for the next link setup phases, e.g.,EAP/802.1x authentication, and/or IP address assignment EAP/802.1x EAPMultiple variants of possible authentication authentication,optimizations, e.g.: & Security plus skipped or shortened, if upperlayer Keys/ session keys are provided parameters Fast EAP using STApre-established setup security association with a network Fast EAPauthentication and Fast Key provisioning using STA pre- establishedsecurity association with a network Fast network discovery and fast EAPauthentication using STA pre-established security association with thenetwork; Fast network discovery, fast EAP authentication, and fast keyprovisioning using STA pre- established security association with anetwork Optimization to a 4-Way handshake protocol by reducing number ofEAPOL-Key frame messages exchanged between the AP and the STA from fourto two. This may be achieved by leveraging a pre- established master keyshared between a network and a STA to derive pairwise master key (PMK)and GMK keys. IP address Assign IP The IP address can be assigned viaassignment address to the the eANDSF over the cellular STA network TheAAA server may send the IP address to the STA in an EAP message.Combined into previous phases, e.g., through piggybacking Layer-2information element Optimized through some fast IP address assignmentschemes

Established security association between a STA and a network, forexample, a cellular network, may be leveraged to enable authenticationand secure link setup on another network, for example, a WLAN network,in an on-demand and seamless fashion. In one example, a reversebootstrap of application-layer credentials on a network may be used togenerate credentials used in a follow-on new access-layer authenticationprocedure in another network. An objective in developing theauthentication mechanisms may be to optimize the steps and proceduresinvolved and facilitate seamless authentication while roaming across allforms of access networks.

An example of using Single Sign-On (SSO) protocols, for example, OpenIDConnect, and reverse bootstrapping may allow a STA to discover andaccess previously unknown networks such as WLAN networks. There may beno need to pre-provision credentials at a new network since these may bebootstrapped from an already running application service security.

Implementation options for SSO integration with WLAN networks mayinclude use of an AAA server that integrates Identity Provider (OP) andenhanced ANDSF (eANDSF) functionalities and an AAA server integrates OPfunctionality.

FIG. 9 is a diagram of an example method 900 in which an AAA server 910may integrate OP and enhanced ANDSF (eANDSF) functionalities to enableseamless authentication and fast link setup. This example may assumethat the STA 920 and the OP unit of the AAA server 910 have alreadyestablished a security association and master keys that may be leveragedfor accessing the WLAN network. On a condition that an associationbetween the STA 920 and the OP unit of the AAA server 910 is notestablished, an active 3GPP connection may be used between the STA 920and the OP unit of the AAA server 910 to exchange OpenID Connectauthentication and generate a master key on both entities.

In a first example, the STA 920 may have successfully completed mutualauthentication 930 towards the OP unit of the AAA server 910 over a 3GPPaccess network and shared Master keys, for example, a pre-shared key(PSK), may have been established on both the STA 920 and OP unit of theAAA server 910. In addition, the STA 920 and the eANDSF unit of the AAA910 may have a mutually authenticated and established secure connection940, for example via a 3GPP enhanced S14 (eS14) interface. The STA 920may request WLAN network information from the eANDSF unit of the AAAserver 910 and/or the eANDSF unit of the AAA server may push WLANnetwork information to the STA over a secure 3GPP connection. Thenetwork information may include available APs, SSIDs, authenticationmethod to use, and other access network parameters. Using theinformation about the available APs and WLAN networks, the STA 920 maynot need to perform passive scanning for beacons or perform a lengthynetwork discovery procedure. The STA 920 may immediately transmit aprobe request 950 to a selected AP 960 from a prioritized list providedto the STA 920 by the eANDSF unit of the AAA server 910.

After the STA 920 receives a probe response 970 from the selected AP960, it may perform open authentication 971 and associate 972 with theselected AP 960. Open authentication 971 may not provide any securitymeasures and may be skipped if an 802.1x/EAP method is used.

The AP 960 may be referred to as the authenticator in this example, andmay issue an EAP Request 973 requesting a STA identity. The STA 920 mayreturn an EAP Response 974 that may include a unique identity, forexample, an international mobile subscriber Identity (IMSI) with itsrealm. The realm may include a hint to use SSO authentication, forexample, IMSI@sso.MNO.com. The AP 960 may transmit an access request 975to an AAA server using, for example, a RADIUS access request. The AccessRequest 975 may include an EAP ID. The OP unit of the AAA server 910 mayrecognize STA identity and correlate it with the existing securityassociation. The OP unit of the AAA server 910 may decide that the STA920 is already authenticated, perform fast EAP authentication, andgenerate a PMK 976 based on the previously generated Master key sharedwith the STA. The AAA server 910 may transmit an Access Accept message977 to the AP 960. The Access Accept message 977 may include an EAPsuccess and the key material to the AP 960. The AP 960 may forward anEAP Success message 978 to the STA 920. The STA 920 may generate a PMK980 using its shared master key with the OP.

The 802.1X/EAP authentication may be completed when the AP 960 transmitsan EAP Success message 978 and the AP 960 may initiate a 4-Way Handshakeprotocol 981 to derive the temporal keys 983, which may include apairwise transient key (PTK) for encryption of unicast traffic and agroup temporal key (GTK) for encryption of broadcast and multicasttraffic. The 4-Way Handshake protocol 981 may use four EAPOL-Key framemessages between the AP 960 and the STA 920.

The 4-Way Handshake may use pseudo-random functions (PRF) to hashvarious inputs to derive pseudo-random values. The PMK may be one of theinputs combined with other inputs to create the PTK on the STA 920 andthe AP 960. Some of the other inputs used by the pseudo-random functionmay be referred to as nonces. A nonce may be a random numerical valuethat is generated one time only, is used in cryptographic operations,and is associated with a given cryptographic key. For the 4-WayHandshake, a nonce may be associated with the PMK. A nonce may only beused once and may not be used again with the PMK. Two nonces may becreated by the 4-Way Handshake, an AP nonce (ANonce) and a supplicantnonce (SNonce). The Snonce may also be referred to as a STA nonce.

To create the PTK, the 4-Way Handshake may use a pseudo-random functionthat combines the PMK, a numerical authenticator nonce, a supplicantnonce, the authenticator's MAC address (AA), and the supplicant's MACaddress (SPA).

In a 4-Way Handshake procedure, the AP and STA may each randomly createtheir respective nonces. The authenticator, for example AP 960, maytransmit an EAPOL-Key frame 982 to the supplicant, for example STA 920.The EAPOL-Key frame 982 may include an ANonce. The STA 920 may now haveall the necessary inputs for the pseudo-random function. The STA 920 mayderive a PTK 983 from the PMK, ANonce, SNonce, and MAC addresses. TheSTA 920 may now be in possession of a PTK that may be used to encryptunicast traffic.

The STA 920 may transmit an EAPOL-Key frame 984 to AP 960. The EAPOL-Keyframe may include an SNonce. The AP 960 may now have all the necessaryinputs for the pseudo-random function. The STA 920 may also transmit itsRSN information element capabilities and a message integrity code (MIC)to the AP 960. The AP 960 may derive a PTK 985 from the PMK, ANonce,SNonce, and MAC addresses. The AP 960 may also validate the MIC. The AP960 may now be in possession of a pairwise transient key that may beused to encrypt unicast traffic.

The AP 960 may derive a GTK 986 from the group master key (GMK) it maypossess. The AP 960 may transmit an EAPOL-Key frame 987 to the STA 920.The EAPOL-Key frame 987 may include the ANonce, the AP's RSN informationelement capabilities, and a MIC. The EAPOL-Key frame 987 may alsoinclude a message to the STA 920 to install the temporal keys. The GTK986 may be delivered inside the unicast EAPOL-Key frame 987 to the STA920. The confidentiality of the GTK 986 may be protected because it maybe encrypted with the PTK 985. The STA 920 may transmit an EAPOL-Keyframe 988 to the AP 960 to confirm that the temporal keys have beeninstalled.

As an optimization to the 4-Way Handshake procedure described above, itmay be possible to reduce the number of EAPOL-Key frame messages betweenthe AP and the STA to two. This may be achieved using any of thefollowing example optimizations. The OP unit of the AAA server and theSTA may leverage the Master key to derive PMK and GMK keys. The AAAserver may transmit both the PMK and the GMK to the AP. The firstmessage of the 4-Way Handshake may be modified to include, in additionto the ANonce, a group nonce (GNonce) randomly generated by the AP. TheSTA may derive a PTK from the PMK, ANonce, SNonce, and MAC addresses.The STA may also derive a GTK from the GMK, GNonce, and MAC addresses.The STA may now be in possession of pairwise transient keys (PTK, GTK)that may be used to encrypt and decrypt unicast, broadcast, andmulticast traffic. The STA may transmit an EAPOL-Key frame including anSNonce to the AP. The STA may also transmit its RSN information elementcapabilities and a message integrity code (MIC) to the AP. The AP mayderive a PTK from the PMK, ANonce, SNonce, and MAC addresses. The AP mayalso derive a GTK from the GMK, GNonce, and MAC addresses. In addition,the AP may validate the MIC.

At one point during the 4-Way Handshake procedure, both the STA and theAP may have PTK and GTK keys that may be used to encrypt and decryptunicast, broadcast and multicast traffic. Thus, the remainder of the4-Way Handshake procedure may not be needed.

At the end of the 4-Way Handshake procedure, the STA 920 may obtain anIP address and necessary configurations 990, for example, one or moredomain name servers (DNS)s to use, using a DHCP protocol, and the STAmay now access the WLAN network 995.

As a variant to achieve optimization for a STA acquiring its IP addressand the necessary configurations, this step may be skipped if the eANDSFprovides the IP address and necessary configuration to the STA over acellular network and the AAA server sends the IP address and necessaryconfigurations to the STA encapsulated into an EAP message, for example,using EAP-Notify message.

FIG. 10 is a diagram of an example method 1000 in which the AAA server1005 integrates OP and eANDSF functionalities to enable seamlessauthentication and fast link setup. This example may assume that the STA1010 and the OP unit of the AAA server 1005 have already establishedsecurity association and master keys that may be leveraged for accessingthe WLAN network. The STA 1010 may have successfully completed mutualauthentication 1015 towards the OP unit of the AAA server 1005 over anetwork that it may have been previously connected to, for example, a3GPP access network, and shared Master keys (PSK) may be established onthe STA 1010 and the OP unit of the AAA server 1005. In addition, theSTA 1010 and the eANDSF unit of the AAA server may be mutuallyauthenticated and a secure connection may be established 1020, forexample over a 3GPP STA-eS14 interface. The STA 1010 may request WLANnetwork info from the eANDSF unit of the AAA server 1005 and/or theeANDSF unit of the AAA server 1005 may push WLAN network information tothe STA 1010 over a secure 3GPP connection. The network information mayinclude available APs, SSIDs, authentication method to use, and otheraccess network parameters. Using the information about the available APsand WLAN networks, the STA 1010 may not need to perform passive scanningfor beacons or perform a lengthy network discovery procedure. The STA1010 may immediately transmit a probe request 1025 to a selected AP 1030from a prioritized list provided to the STA 1010 by the eANDSF unit ofthe AAA server 1005.

After the STA 1010 receives a probe response 1035 from the selected AP1030, it may perform open authentication 1040 and associate 1041 withthe selected AP 1030. Open authentication 1040 may not provide anysecurity measures and may be skipped if an 802.1x/EAP method is used.

The AP 1030 may be referred to as the authenticator in this example, andmay issue an EAP Request 1042 requesting a STA identity. The STA 1010may return an EAP Response 1043 that may include a unique identity, forexample, an international mobile subscriber Identity (IMSI) with itsrealm. The realm may include a hint to use SSO authentication, forexample, IMSI@sso.MNO.com. The AP 1030 may transmit an access request1044 to an AAA server 1005 using, for example, a RADIUS access request.The Access Request 1044 may include an EAP ID.

The OP unit of the AAA server 1005 may determine that the STA 1010 needsto be re-authenticated before sending an Access Accept message to theAP. Therefore, one or more rounds of EAP-Challenge/Response messages maybe exchanged before sending an EAP-Success and keying material to theAP. For example, the AAA server 1005 may generate a challenge based on aSTA-OP PSK 1045 and transmit an access challenge message 1046 to AP1030. The access challenge message 1046 may include an EAP ID and/or anEAP challenge. The AP 1030 may transmit an EAP-Request message 1047 toSTA 1010 in response to the access challenge message 1046. TheEAP-Request message 1047 may include an identity and/or a challenge. TheSTA 1010 may receive the EAP-Request message 1047, verify the MAC andgenerate an SRES 1048, and transmit an EAP-Response message 1049 to theAP 1030. The EAP-Response message 1049 may include an identity and/or aresponse to the challenge.

The AP 1030 may transmit an access request message 1050 to the AAAserver 1005, and receive an access accept message 1051 from the AAAserver 1005 in response. The access request message 1050 may include anEAP ID and/or a response to the challenge. The access accept message1051 may include an EAP ID, an indication of success, and the PMK key tothe AP. In response to receiving the access accept message 1051, the AP1030 may transmit an EAP-Success message 1052 to the STA 1010. Inresponse to receiving the EAP-Success message 1052, the STA 1010 maygenerate a PMK 1053 using the STA-OP PSK and may perform a 4-wayhandshake protocol 1054 with the AP 1030, request IP address assignmentusing DHCP 1055, and access the internet over WLAN 1056, as described inFIG. 9 above.

FIG. 11 is a diagram of an example method 1100 in which the AAA server1101 integrates OP functionality to enable seamless authentication andFILS. The example in FIG. 11 may assume that the STA 1102 and the OPunit of the AAA server 1101 have already established securityassociation and master keys that may be leveraged for accessing the WLANnetwork. The STA 1102 may have successfully completed mutualauthentication towards the OP over, for example, the 3GPP accessnetwork, and shared Master keys (PSK) may be established on the STA 1102and the OP unit of the AAA server 1101. The STA 1102 may not haveconnectivity to an eANDSF and, therefore, may perform WLAN networkdiscovery through other mechanisms, for example, using 802.11u.

In the example shown in FIG. 11, during a fast EAP procedure, the OPunit of the AAA server 1101 may recognize a STA identity and correlateit with an existing security association. The OP unit of the AAA server1101 may determine that the STA 1102 is already authenticated, performfast EAP authentication, and generate PMK based on the previouslygenerated Master key shared with the STA 1102.

For example, the STA 1102 may have successfully completed mutualauthentication 1103 towards the OP unit of the AAA server 1101 over anetwork that it may have been previously connected to, for example, a3GPP access network, and shared Master keys (PSK) may be established onthe STA 1102 and the OP unit of the AAA server 1101. The STA 1102 mayperform passive and/or active AP discovery 1104 as described in FIG. 9.The STA 1102 may perform one or more GAS message exchanges to performNetwork discovery 1105. For example, the STA 1102 may transmit a GASmessage 1106 to AP 1107, and receive a GAS response message 1108 fromthe AP 1107 in response.

The STA 1102 may perform open authentication 1109 and associate 1110with the selected AP 1107. Open authentication 1109 may not provide anysecurity measures and may be skipped if an 802.1x/EAP method is used.

The AP 1107 may be referred to as the authenticator in this example, andmay issue an EAP Request 1112 requesting a STA identity. The STA 1102may return an EAP Response 1113 that may include a unique identity, forexample, an international mobile subscriber Identity (IMSI) with itsrealm. The realm may include a hint to use SSO authentication, forexample, IMSI@sso.MNO.com. The AP 1107 may transmit an access request1114 to an AAA server 1101 using, for example, a RADIUS access request.The Access Request 1114 may include an EAP ID.

The AAA server 1101 may generate a PMK from the STA-OP PSK 1115, andtransmit an Access Accept message 1116 to the AP 1107. The Access Acceptmessage 1116 may include an EAP ID, an indication of success, and thePMK key to the AP. The AP 1107 may transmit an EAP Success message 1119to the STA 1102. In response, the STA 1102 may generate a PMK using theSTA-OP PSK 1120 and may perform a 4-way handshake protocol 1121 with theAP 1107, request IP address assignment using DHCP 1122, and access theinternet over WLAN 1123, as described in FIG. 9 above.

FIG. 12 is a diagram of an example method 1200 in which a AAA server1201 may integrate OP functionality to enable seamless authenticationand FILS. This example may assume that the STA 1202 and the OP unit ofthe AAA server 1201 have already established security association andmaster keys that may be leveraged for accessing the WLAN network. TheSTA 1202 may have successfully completed mutual authentication 1203towards the OP unit of the AAA server 1201 over, for example, a 3GPPaccess network, and shared Master keys, for example, PSK, may beestablished on the STA 1202 and the OP unit of the AAA server 1201. TheSTA 1202 may not have connectivity to an eANDSF and, therefore, mayperform WLAN network discovery through other mechanisms, for example,using 802.11u.

Referring to FIG. 12, the STA 1204 may perform passive and/or active APdiscovery 1205 as described in FIG. 9. The STA 1202 may perform one ormore GAS message exchanges to perform Network discovery 1206. Forexample, the STA 1202 may transmit a GAS message 1207 to AP 1204, andreceive a GAS response message 1208 from the AP 1204 in response.

The STA 1202 may perform open authentication 1209 and associate 1210with the selected AP 1204. Open authentication 1209 may not provide anysecurity measures and may be skipped if an 802.1x/EAP method is used.

The AP 1204 may be referred to as the authenticator in this example, andmay issue an EAP Request 1211 requesting a STA identity. The STA 1202may return an EAP Response 1212 that may include a unique identity, forexample, an international mobile subscriber Identity (IMSI) with itsrealm. The realm may include a hint to use SSO authentication, forexample, IMSI@sso.MNO.com. The AP 1204 may transmit an Access Request1213 to the AAA server 1201 using, for example, a RADIUS access request.The Access Request 1213 may include an EAP ID.

The OP unit of the AAA server 1201 may determine that the STA 1202 needsto be re-authenticated before transmitting an Access Accept message tothe AP 1204. Accordingly, one or more rounds of EAP-Challenge/Responsemessages may be exchanged before transmitting an EAP-Success message andkeying material to the AP 1204. For example, the AAA server 1201 maygenerate a challenge based on a STA-OP PSK 1214 and transmit an accesschallenge message 1215 to AP 1204. The access challenge message 1215 mayinclude an EAP ID and/or an EAP challenge. The AP 1204 may transmit anEAP-Request message 1215 to STA 1202 in response to the access challengemessage 1215. The EAP-Request message 1216 may include an identityand/or a challenge. The STA 1202 may receive the EAP-Request message1216, verify the MAC and generate an SRES 1217, and transmit anEAP-Response message 1218 to the AP 1204. The EAP-Response message 1218may include an identity and/or a response to the challenge.

The AP 1204 may transmit an access request message 1219 to the AAAserver 1201, and receive an access accept message 1220 from the AAAserver 1201 in response. The access request message 1219 may include anEAP ID and/or a response to the challenge. The access accept message1220 may include an EAP ID, an indication of success, and the PMK key tothe AP. In response to receiving the access accept message 1220, the AP1204 may transmit an EAP-Success message 1221 to the STA 1202. Inresponse to receiving the EAP-Success message 1221, the STA 1202generate a PMK 1222 using the STA-OP PSK, and may perform a 4-wayhandshake protocol 1223 with AP 1204, request IP address assignmentusing DHCP 1224, and access the internet over WLAN 1225, as described inFIG. 9 above.

FIG. 13 is a diagram of an example method 1300 for a pre-establishedsecurity association between a STA 1301 and a network to enable seamlessauthentication and fast initial link setup. In this example, Fast EAPmay be encapsulated into 802.11 Authentication frames. This may assumethat the STA 1301 and the network, for example an AAA server 1302 withintegrated OP functionality, have already established securityassociation and master keys that may be leveraged for secure access tothe WLAN network. The STA may have successfully completed mutualauthentication 1303 towards the AAA/OP over 3GPP access network andshared Master keys (PSK), and FILS Identity 1304 may have beenestablished on both the STA 1301 and AAA server 1302.

In this example, the 802.11 Authentication frames may encapsulate FastEAP messages between the STA 1301 and the AP 1305. In addition Snonceand Anonce may be exchanged using the Authentication frames, which mayenable a 4-Way Handshake Protocol to be performed concurrently. Forexample, the STA 1301 may generate a Snonce 1306 and transmit anauthentication message 1307 to the AP 1305. The authentication message1307 may include an EAP Response message, and indicate a sequencenumber, FILS ID, Snonce, and/or an Auth-tag.

The AP 1305 may store 1308 the Snonce and transmit an access requestmessage 1309 to the AAA server 1302. The access request message 1309 maybe an EAP message, and may include a FILS ID, a sequence number (SEQ),and/or an Auth-tag.

The AAA server 1302 may use the FILS identity to look up thepre-established security context with the STA 1301. The AAA server 1302may verify the sequence number. The server may then proceed to verifythe integrity of the message using the integrity key, thereby verifyingproof of possession of that key by the peer. If all verifications aresuccessful, the AAA server 1302 may generate a PMK 1310 from a STA-OPPSK and transmit an access accept message 1311 to the AP 1305. Theaccess accept message may include a session key, for example a PMK, anEAP-Success message, an SEQ, a FILS ID, a Channel binding information(CB-Info) field, and/or an authentication tag (Auth-tag). The Auth-tagmay enable a receiver, for example a STA or an AAA server, to verify theintegrity of the received message and determine its validity. The AAAserver 1302 may transmit CB-Info in an EAP message (not shown) so thatthe STA may verify that the EAP message was received via the correct APand not a compromised AP.

If the STA 1301 includes an optional [IP_CFG_REQ] field in theauthentication message 1307, the AAA server 1302 may transmit the IPconfigurations to the STA 1301 in an [IP_CFG_Reply] field of theEAP-Success message. Note that the brackets may indicate optionalfields.

In addition, the AAA server 1302 may transmit Channel bindinginformation [CB-Info] in the EAP-Success message so that the STA 1301may verify that the EAP message was received via the correct AP and nota compromised one.

In response to receiving the access accept message 1311, the AP 1305 mayderive a PTK 1312 from the PMK, Anonce, and/or Snonce, and generate aGTK. The AP 1305 may transmit an authentication message 1313 to the STA1301. The authentication message 1313 may include, for example, an EAPSuccess message that may indicate an SEQ, FILS ID, CB-Info, Anonce,and/or an Auth-tag.

In response to receiving the authentication message 1313, the STA 1301may derive a PTK 1314 and install the GTK. At the end of successfulauthentication, the STA 1301 and the AP 1305 may have the (PTG, GTK)Keys ready to protect data exchanged between STA 1301 and the AP 1305over the 802.11 radio 1315.

In the case where the STA 1301 may not have the necessary IPconfigurations, the STA 1301 may use, for example, an 802.11 Associationframe exchange to provide the necessary IP address configurations forthe FILS authenticated STA such that it may be ready to launchapplications, for example, internet browsing, or switch ongoing sessionsfrom one network, for example, 3GPP, to the WLAN network securely. Forexample, the STA 1301 may transmit an association message 1316 to the AP1305, and receive an association message 1317 in response from the AP1305. The association message 1316 may include an [IP-CFG-REQ] field,and the association message 1317 may include an [IP-CFG-Reply] field.

FIG. 14 is a diagram of an example method 1400 for a pre-establishedsecurity association between a STA 1401 and a network, for example, anAAA server 1402 to enable seamless authentication and fast initial linksetup. In this example, Fast EAP may be encapsulated into 802.11Association frames. The AAA server 1402 may be configured to perform OPfunctions.

This example may assume that the STA and the AAA server 1402 havealready established security association and master keys that may beleveraged for secure access to the WLAN network. It may be assumed thatthe STA 1401 successfully completed mutual authentication 1403 towardsthe OP unit of the AAA server 1402 over a 3GPP access network and thatshared Master keys (PSK) and FILS Identity 1404 are established on boththe STA 1401 and AAA server 1402.

In this example, the STA 1401 may generate an Snonce 1405, and transmitan association frame 1406 to the AP 1407. The association frame 1406 mayinclude an EAP message, and indicate an SEQ, FILS ID, [IP-CFG-REQ],Snonce 1405, and/or an Auth-tag. The AP 1407 may receive the associationframe 1406 and store 1408 the Snonce 1405. The AP 1407 may transmit anaccess request frame 1409 to the AAA server 1402. The access requestframe 1409 may include an EAP-Response message, and indicate an SEQ,FILS ID, [IP-CFG-REQ], and/or Auth-tag.

In response to receiving the access request frame 1409, the AAA server1402 may generate 1410 a PMK from the STA-OP PSK. The AAA server 1402may transmit an access accept frame 1411 to the AP 1407. The accessaccept frame 1411 may include a PMK and/or an EAP-Success message, andindicate an SEQ, FILS ID, [IP-CFG-Reply], [CB-Info], and/or an Auth-tag.

In response to receiving the access accept frame 1411, the AP 1407 mayderive 1412 a PTK from the PMK, Anonce, and/or Snonce, and generate aGTK. The AP 1407 may transmit an association frame 1413 to the STA 1401.The association frame 1413 may include an EAP-Success message, andindicate an SEQ, FILS ID, [CB-Info], Anonce, [IP-CFG-Reply], and/or anAuth-tag. The STA 1401 may derive 1414 a PTK and install the GTK andaccess the internet over the WLAN 1415.

In this example, the 802.11 Association frames may include at least thefollowing: (1) Fast EAP messages between the STA and the AP; (2) Snonceand Anonce needed to complete the 4-Way Handshake Protocol concurrently;(3) [IP-CFG-REQ] from the STA to the AP and [IP-CFG-Reply] from the APto the STA for concurrent IP address assignment. At the end ofassociation, the FILS authenticated STA may have the necessary IPaddress configurations to access the WLAN network securely.

FIG. 15. is a diagram of an example method 1500 for a pre-establishedsecurity association between a STA 1501 and a network, for example anAAA server 1502, to enable seamless authentication and fast link setup.This example may be based on a Non-EAP FILS Authentication. The AAAserver 1502 may be configured to perform OP and/or eANDSF functions.

This example may assume that the STA 1501 and the AAA server 1502 havealready established security association and master keys that may beleveraged for secure access to the WLAN network. It may be assumed thatthe STA 1501 successfully completed mutual authentication 1503 towardsthe OP unit of the AAA server 1502 over, for example, a 3GPP accessnetwork, and that a shared Master keys (PSK) and FILS Identity areestablished 1504 on both the STA 1501 and AAA server 1502.

In this example, the 802.11 Authentication frames carry non-EAPAuthentication messages between the STA 1501 and the AP 1505. Inaddition Anonce may be transmitted from the AP 1505 to the STA 1501using the Authentication frames which may enable the STA 1501 to derivePTK.

The 802.11 Association frames may carry a Snonce from the STA 1501 tothe AP 1505 such that the AP 1505 may derive a PTK on its side. Inaddition, the Association frames may carry an optional IP configurationrequest [IP-CFG-REQ] from the STA 1501 to the AP 1505 and [IP-CFG-Reply]from the AP 1505 to the STA 1501. At the end of association, the FILSauthenticated STA has the necessary IP address configurations to accessthe WLAN network securely.

For example, the STA 1501 may transmit an authentication message 1506 tothe AP 1505. The authentication message 1506 may include an SEQ, FILSID, and/or an Auth-tag. In response to receiving the authenticationmessage 1506, the AP 1505 may transmit an access request message 1507 tothe AAA server 1502. The access request message 1507 may include an SEQ,FILS ID, and/or an Auth-tag. The AAA server may generate 1508 a PMK fromthe STA-OP PSK, and transmit an access accept message 1509 to the AP1505. The access accept message may include a PMK, SEQ, FILS ID,[CB-Info], and/or an Auth-tag.

In response to receiving the access accept message 1509, the AP 1505 maytransmit an authentication message 1510 to the STA 1501. Theauthentication message 1510 may include an SEQ, [CB-Info], Anonce,and/or an Auth-tag. The STA 1501 may generate 1511 an Snonce, derive aPTK, and transmit an association message 1512 to the AP 1505. Theassociation message 1512 may include an Snonce, [IP-CFG-REQ], and/or anAuth-tag.

The AP 1505 may derive 1513 a PTK from the PMK, Anonce, and Snonce, andgenerate a GTK. The AP 1505 may transmit an association message 1514 tothe STA 1501. The association message 1514 may include a GTK,[IP-CFG-Reply], and/or an Auth-tag. In response to receiving theassociation message 1514, the STA 1501 may install the GTK 1515, andaccess the internet securely over the WLAN 1516.

At the end of the AP discovery phase, ALS capable STAs and APs maynegotiate ALS post-AP-discovery procedures based on the availability andamount of information the STAs and APs have pre-acquired about eachother. This pre-acquired information may include, for example, one ormore of network services information, TSF Information, 802.11authentication and association information, EAP/802.1x authenticationand security information, and IP address assignment information. Basedon this available pre-acquired information, the STA or the AP mayinitiate negotiation of customized post-AP-discovery procedures.

Examples of signaling used for the Post-AP-Discovery procedurenegotiations are shown in Table 3, where potential actions in each phaseof the Post-AP-Discovery linkset up process are listed and expressed bya binary sequence. A sequence of numbers beginning with “0b” in Table 3may indicate that the numbers after “0b” is an expression in the binaryformat.

TABLE 3 Examples of Negotiation Signaling Phase # bits Details Network 30b000: 802.11u Discovery 0b001: 802.11u-plus 0b010-0b110: reserved0b111: skip Network Discovery Phase Additional 1 0b0: unchanged TSF 0b1:skip Additional TSF 802.11 2 0b00: unchanged Authentication 0b01-0b10:Reserved 0b1l: skip 802.11 Authentication Phase 802.11 2 0b00: unchangedAssociation 0b01: updated to carry more information elements; 0b10:reserved 0b11: skip 802.11 Association Phase EAP/802.1x 4 0b0000:unchanged Authentication 0b0001: use fast EAP authentication & Security0b0010: use Fast EAP authentication and fast key provisioning 0b0011:Fast network discovery and fast EAP authentication; 0b0100: Fast networkdiscovery, fast EAP authentication, and fast key provisioning.0b0101-0b1110: reserved 0b1111: skip EAP/802.1x Authentication &Security Phase IP Address 3 0b000: unchanged; Assignment 0b001: do it inLayer-2 messages, 0b010-0b110: reserved 0b111: skip IP addressassignment Phase

An implementation of post-AP-discovery negotiation signaling may bemulti-fold. For example, post-AP-discovery negotiation may beimplemented using the FILS management action frame described above,where the negotiation signaling code for each phase of the post-APdiscovery may be located in a corresponding field in the FILS managementaction frame. In another example, the negotiation signaling codes may beimplemented as a bit map in IEs of AP discovery messages, for example,in the I-Know-You IE and/or I-know-you-response IEs. In another example,the negotiation signaling codes may be implemented in IEs included inother management and control frames, such as beacon, probe requests andprobe responses.

Using the example encoding in Table 3, a 15-bit ALS information fieldmay be included by the STA or the AP to express its most optimizedpost-AP-discovery link setup procedure. The ALS information field may besegmented into different sizes of segments, each segment correspondingto a post-AP-discovery link setup phase. The bit order in the identifiermay be the same order of the functional phases illustrated in Table 3,for example, bits 14 and 13 corresponding to network a discovery phase.

If, for example, the AP has pre-acquired identity information of acandidate STA, such as the MAC address and/or service need information,the AP may determine that the network discovery, additional TSF, and802.11 authentication phases may be skipped and the link setup procedureshould go through the 802.11 association, EAP authentication, and/orDHCP-based IP address assignment phases when the AP receives a framefrom the STA, for example, a probe request frame. The AP may, therefore,transmit a probe response frame to the STA with an I-know-you IEincluding a 15-bit Post-AP-discovery procedure code of “0b111 1110 00000000”. If the STA receives such a post-AP-discovery procedure code, theSTA may either transmit an I-know-you-response IE with the same orrevised code in a management frame to confirm or revise thepost-AP-discovery procedure, or it may implicitly accept it by directlyproceeding to the next phase as suggested by the code, for example,802.11 association. In this way, the AP may initiate the link setupoptimizations by using its pre-acquired knowledge about the STA.

In another example, when a STA includes the ALS Information Field “0b111111 01 0010 001” for its ALS Post-AP-Discovery procedure in its proberequest frame to a preferred AP, the STA may be indicating to the AP oneor more of the following: the most optimized ALS post-AP-discoveryprocedure with this particular AP may include the phases of networkdiscovery, and additional TSF and 802.11 authentication may be skipped;a modified 802.11 association phase may be used; a fast EAPauthentication and fast key provisioning scheme may be used; and/or anoptimized IP address assignment may be used, for example, by carryingone or more DHCP messages in one or more Layer-2 messages. The APreceiving a probe request that indicates that the STA is a STA withpre-acquired information, may transmit a probe response frame using asimilar sequence depending on the amount of information the AP haspre-acquired about the STA. The STA receiving the probe request mayrespond by transmitting a FILS management action frame to confirm theagreed optimized and customized ALS post-AP-discovery procedure.

When an AP and a STA negotiate the post-AP-discovery procedure, if forone or more phases of the link setup processes of the AP and STA havedifferent requirements, then the stricter requirement may prevail. Anexample of the different requirements may be where the STA may requestto skip the network discovery phase while the AP may request an 802.11unetwork discovery phase. In this example, the STA may agree to an802.11u network discovery phase at the request of the AP. In addition,the final agreed upon optimized ALS post-AP-discovery procedure may bepositively confirmed for the correct functioning of the ALS. Such aconfirmation may be achieved by transmitting a FILS management actionframe including the agreed ALS post-AP-discovery procedure and an ALSinformation field indicating the agreed upon ALS post-AP-discoveryprocedure in a unicast frame, such as a probe request frame, a proberesponse frame, an association request frame, etc., to the correspondingSTA or AP.

Another example method may include using pre-acquired systemconfiguration knowledge. The system configuration for this example maybe referred to as a set of system parameters that are either static orsemi-static for a specific system deployment and operational mode. Suchsystem parameters may also be referred to as system configurationparameters, and the “system” in this context may refer to the IEEE802.11-based Wireless LAN systems.

The system configuration may be pre-acquired by the STA prior toinitiating a link setup process with a BSS/AP, and it may be used toaccelerate the initial link setup process.

System configuration parameter sets may be defined. For example, tospecify the operational mode of a Wireless LAN system, the followingthree different configurations may be defined and used: (1) BSS/APconfiguration, also referred to as the BSS configuration or APconfiguration; (2) Access Network configuration; and (3) CombinedAP/Network configuration also referred to as the AP/Networkconfiguration.

Each of the above configurations may contain a set of system parametersthat specifies the corresponding system operational settings. The APconfiguration parameter set may include the BSS/AP operationalparameters/descriptors that are static or semi-static over time withregard to value changes.

In order to use system configuration information as pre-acquiredknowledge to accelerate the link setup process, the following basiccriteria may be applied to select the AP configuration parameters: (a)the parameters that may be used to start a BSS/AP operation, forexample, the parameters used in the MLME_START.request primitives in802.11; (b) the parameters that may be used to specify BSS/AP operationsettings that may be communicated between an AP and STAs, for example,in a Beacon frame or Probe Response frame, etc.; (c) the parameters thatmay not dynamically change the values overtime, for example, keeping thesame values for hours, days, even months; and/or (d) the parameters thatmay be relevant for link setup.

Based on the basic selection criteria, Table 4 below provides an exampleof an infrastructure BSS/AP configuration parameter set.

TABLE 4 An Example of Infrastructure BSS/AP Configuration Parameter SetValue Parameter present Valid Value Additional Name indicator RangeDescription Notes BSSID Must 6-byte MAC 6-byte MAC address of the AP inMAC frame present address of the STA header sent by AP STA the AP STASSID Must Octet string, The SSID of the BSS. in Beacon/ present 0-32octets Probe Response/FD frame SSIDEncoding Present/ Enumeration: Theencoding used for the in the exended Not- UNSPECIFIED, SSID capabilityIE Present Universal in Beacon/ Character Set Probe (UCS) Response;Transformation Format 8 (UTF8). This value may be an 8 bit value.BSSType Present/ Enumeration: The type of the BSS. in the Not-INFRASTRUCTURE, capability IE Present INDEPENDENT, in Beacon/ MESH ProbeResponse; BeaconPeriod Present/ Integer: >=1 The Beacon period (in TimeBeacon Not- Unit (TU)) of the BSS. Interval in Present Beacon/ProbeResponse. Contention Present/ The CF The parameter set for CF in Beacon/Free (CF) Not- Parameter periods, if the BSS supports Probe parameterPresent Set element CF mode. Response set contains the set of parametersnecessary to support the point coordination function (PCF). TheInformation field contains the CFPCount, CFPPeriod, CFPMaxDuration, andCFPDurRemaining fields. The total length of the Information field is 6octets. PHY Present/ The The parameter sets relevant in Beacon/parameter Not- Information to the PHY Probe set Present field mayResponse contain Dwell Time, Hop Set, Hop Pattern, and Hop Indexparameters. The total length of the Information field may be 5 octets.Alternatively, the Information field may contain a single parametercontaining the dot11CurrentChan- nel, and may be 1 octet in length.CapabilityIn- Present/ The length of The capabilities to be in Beacon/formation Not- the advertised for the BSS. Probe Present CapabilityResponse Information field may be 2 octets. BSSBasicRateSet Present/ Setof The set of data rates that in the Not- Integers: shall be supportedby all STAs Supported Present 1-127 to join this BSS. The STA that RatesIE in inclusive (for is creating the BSS shall be Beacon/Probe eachinteger able to receive and transmit Response in the set) at each of thedata rates listed in the set. Operation- Present/ Set of The set of datarates that the in the alRateSet Not- Integers: STA desires to use forSupported Present 1-127 communication within the Rates IE, inclusive(for BSS. The STA shall be able to extended each integer receive at eachof the data supported in the set) rates listed in the set. This setRates IE, is a superset of the rates and/or ERP IE contained in the inBeacon/ BSSBasicRateSet parameter. Probe Response Country Present/ Thelength The information required to in Beacon/ Not- may be 6 to 7identify the regulatory Probe Present octets. domain in which the STA isResponse located and to configure its PHY for operation in thatregulatory domain. EDCAParameterSet Present/ The length The initialenhanced in Beacon/ Not- may be 20 distributed channel access ProbePresent octets. (EDCA) parameter set values Response to be used in theBSS. DSERegisteredLo- Present/ The length The information for the datain Beacon/ cation Not- may be 22 service element (DSE) Probe Presentoctets. Registered Location element. Response High Present/ The lengthThe HT capabilities to be in Beacon/ Throughput Not- may be 28advertised for the BSS. Probe (HT) Present octets. Response CapabilitiesHT Operation Present/ The length The additional HT capabilities inBeacon/ Not- may be 24 to be advertised for the BSS. Probe Presentoctets. Response BSSMember- Present/ set of The BSS membership includedas shipSelectorSet Not- integers: A selectors that represent the onevalue Present value from set of features that shall be setting in Table8-55 for supported by all STAs to join Supported each member this BSS.The STA that rate IE, in of the set. creating the BSS shall be ableBeacon/Probe to support each of the features Response represented by theset. BSSBasicMCSSet Present/ set of The set of modulation and includedas Not- integers: coding scheme (MCS) values one subfield in PresentEach that shall be supported by all the HT representing HT STAs to jointhis BSS. The operation IE an MAC STA that is creating the BSS inBeacon/ index value shall be able to receive and Probe in the range 0transmit at each of the MCS Response to 76. values listed in the set.HTOperation- Present/ set of The set of MCS values that included asalMCSSet Not- integers: the STA desires to use for one subfield inPresent Each communication within the the HT representing BSS. The STAshall be able to capability IE an MAC receive at each of the data inBeacon/ index value rates listed in the set. This set Probe in the range0 is a superset of the MCS Response. to 76. values contained in theBSSBasicMCSSet parameter. Extended Present/ The length Specifies theparameters in Beacon/ Capabilities Not- may be within the Extended ProbePresent variable. Capabilities element that are Response supported bythe MAC entity. 20/40 BSS Present/ The length Specifies the parametersin Beacon/ Coexistence Not- may be 3 within the 20/40 BSS Probe Presentoctets. Coexistence element that are Response indicated by the MACentity. Overlapping Present/ The length Specifies the parameters inBeacon/ BSS Scan Not- may be 16 within the Overlapping BSS ProbeParameters Present octets. Scan Parameters element that Response areindicated by the MAC entity. MultipleBSSID Present/ The length Specifythe multiple BSSID in Beacon/ Not- may be information when the AP is aProbe Present variable. member of a Multiple BSSID Response Set with twoor more members. Interworking Present/ The length Specifies theInterworking in Beacon/ Info Not- may be 3, 5, capabilities of STA.Probe Present 9, or 11 Response octets. Advertisment Present/ 0-255Identifies zero or more in Beacon/ ProtocolInfo Not- AdvertisementProtocols and Probe Present advertisement control to be Response used inthe BSSs. RoamingConsor- Present/ The length Specifies identifying inBeacon/ tiumInfo Not- may be information for subscription Probe Presentvariable. service provider (SSP)s whose Response security credentialscan be used to authenticate with the AP. Power Present/ The lengthcontains the information in Beacon/ Constraint Not- may be 3 necessaryto allow a STA to Probe Present octets. determine the local maximumResponse transmit power in the current channel. RSN Present/ The lengthcontains authentication and in Beacon/ Not- may be up to pairwise ciphersuite Probe Present 255 octets. selectors, a single group data Responsecipher suite selector, an RSN Capabilities field, the PMK identifier(PMKID) count, a PMKID list, and a single group management cipher suiteselector. AP Channel Present/ The length contains a list of channels inBeacon/ Report Not- may be where a STA is likely to find Probe Presentvariable. an AP. Response Supported Present/ The length advertise theoperating in Beacon/ Regulatory Not- may be classes that it is capableof Probe Classes Present between 2 operating in the country. Responseand 253 octets. VendorSpecif- Present/ The length containingvendor-specific in Beacon/ icInfo Not- may be information. Probe Presentvariable. Response

The example BSS/AP configuration parameter set above is per BSS/AP thatis identified by the BSSID, for example the 6-byte MAC address of theAP.

As shown in Table 4, each parameter in the AP configuration parameterset has a present-indicator to indicate whether or not the value of theparameter is present in a specific configuration instance. Aconfiguration instance may be referred to as a configuration indicator.This may allow a subset of the parameters in the configuration set tospecify a specific BSS/AP operation mode with the use of a specific PHYmode and/or the selection of certain optional system features andfunctionalities, for example, QoS support, Interworking services, etc.

The Access Network configuration parameter set may include the static orsemi-static operational parameters or descriptors of the access networkbehind the BSS/AP that may be relevant to link setup of STAs. Similarly,in order to use the access network configuration information as thepre-acquired knowledge to accelerate the link setup process, thefollowing basic criteria may be applied to select the access networkconfiguration parameters: (a) the parameters that may be used to specifythe access network services, capabilities, attributes, and/orfunctionalities, for example, those parameters used in the accessnetwork discovery messages, such as access network query protocol(ANQP/GAS; (b) the parameters that may not dynamically change the valuesovertime, for example, keeping the same values for hours, days, evenmonths; and/or (c) the parameters that may be relevant for link setup.

Based on the above selection criteria, Table 5 below provides an exampleaccess network configuration parameter set.

TABLE 5 An Example of Access Network Configuration Parameter SetParameter Present Name Indicator Description Venue Name Present/Provides zero or more venue names information not-present associatedwith the BSS. Emergency Call Present/ provides a list of emergency phoneNumber not-present numbers to an emergency responder, information suchas directed by a public safety answering point (PSAP), that is used inthe geographic location of the STA. Network Present/ provides a list ofauthentication types. Authentication not-present Type Roaming Present/provides a list of information about the Consortium not-present RoamingConsortium and/or SSPs whose networks are accessible via this AP. IPAddress Type Present/ provides STA with the information Availabilitynot-present about the availability of IP address version and type thatcould be allocated to the STA after successful association. NAI RealmPresent/ provides a list of network access not-present identifier (NAI)realms corresponding to SSPs or other entities whose networks orservices are accessible via this AP; optionally included for each NAIrealm is a list of one or more EAP Method subfields, which that NAIrealm uses for authentication. 3GPP Cellular Present/ contains cellularinformation such as Network not-present network advertisementinformation e.g., network codes and country codes to assist a 3GPPnon-AP STA in selecting an AP to access 3GPP networks. AP GeospatialPresent/ provides the AP's location in LCI Location not-present(Location Configuration Information) format, which includes Latitude,Longitude, Altitude, and optional Azimuth information. AP Civic Present/provides the AP's location in Civic Location not-present format. APLocation Present/ provides an indirect reference to the PublicIdentifier not-present location information for the AP. URI Domain NamePresent/ provides a list of one or more domain not-present names of theentity operating the IEEE 802.11 access network. Emergency AlertPresent/ provides a Uniform Resource Identifier Identifier URInot-present (URI) for EAS message retrieval. Tunneled Direct Present/Contains the information to be used by Link Setup not-present a STA todiscover the TDLS (TDLS) capabilities of a peer STA. capabilityEmergency NAI Present/ contains an emergency string, which isnot-present available for use by a STA as its identity to indicateemergency access request. Neighbor Report Present/ provides zero or moreneighbor reports not-present about neighboring APs. vendor-specificPresent/ Contains vendor specific information not-present about theaccess network.

Similarly, the above access network configuration parameter set may beper BSS/AP, where the access network may be the network that the STA mayconnect to through the Wireless LAN of the BSS/AP. Also, as shown inTable 5, for each parameter in the access network configurationparameter set, a present-indicator may be used to indicate whether ornot the value of the parameter is present in a specific configurationinstance, such that a subset of configuration parameters may be allowedto specify a specific network operation with the selected optionalfeatures and functionalities, for example, emergency alert service, etc.

As an alternative to defining separate AP and network configurationparameter sets, a combined single AP/Network configuration parameter setmay be defined to specify the operation settings and services of boththe AP and access network. The combined single AP/Network configurationparameter may contain the operational parameters/descriptors for boththe BSS/AP and the access network.

The selection criteria of a combined AP/Network configuration parameterset may be a combination of the AP configuration parameter selectioncriteria and the access network configuration selection criteria. Inaddition, the two parameter sets in Table 4 and Table 5 may be combinedto provide an example of a combined AP/network configuration parameterset.

A system configuration instance with a configuration change count may beidentified. A system configuration instance may refer to a configurationparameter set with specific values assigned to each of the configurationparameters. The configuration parameters may be used to specify acorresponding system operational mode. If a configuration parameter setmay be defined for a system with optional features or functionalities,and a configuration instance may include a subset of configurationparameters with valid values, while the remaining parameters may bemarked as “not-present.”

Any changes to a configuration instance may result in a newconfiguration instance, for example, a parameter value change, or a“not-present” parameter changed to “present” with a valid valueassigned, or a “present” parameter changed to “not-present,” etc. Aconfiguration instance may be identified by its version number, alsoreferred to as a Configuration Change Count (CCC), or a ConfigurationSequence Number (CSN). The CCC may be an integer variable whose valuemay change every time a configuration instance changes. The CCC may bechanged based on a pre-defined function. One example may be that the CCCincrements by 1 every time a configuration instance changes and wrapsaround to 0 once reaching its maximum value.

A BSS/AP configuration may be defined per BSS/AP, which may beidentified by the BSSID, for example, the MAC address of the AP. An APConfiguration Change Count (AP-CCC) may be used to identify an instanceof AP configuration. Accordingly, a combination of BSSID, configurationtype, and/or AP-CCC, for example, may be used to identify aconfiguration instance of the given AP, where the configuration type mayindicate a specific configuration among the multiple configurations thatmay be defined and used, for example, BSS/AP configuration, accessnetwork configuration, etc.

Similarly, an integer variable, such as an Access Network ConfigurationChange Count (AN-CCC), may be used to identify the version number of anAccess Network configuration instance. A combination of BSSID,configuration type, and/or AN-CCC, may be used to identify aconfiguration instance of the access network through an AP.

If a combined AP/Network configuration is used, then an integervariable, such as an AP/Access Network Configuration Change Count(AP/AN-CCC), may be used to identify the version number of a combinedconfiguration instance. For example, a combination of BSSID,configuration type, and/or AP/AN-CCC, may be used to identify aconfiguration instance of an AP and the access network through the AP.

System information communication may be performed with pre-definedsystem configuration parameter sets. In Wireless LAN systems, the systeminformation, for example, the BSS/AP operational parameters, accessnetwork functionalities, and/or attributes, etc., may be communicated toSTAs for initial link setup and for link resumption when returning frompower saving modes. The system configuration parameter sets may bedefined to improve the efficiency of the system informationcommunication between AP/Network and the STAs.

When system configurations are used to facilitate efficient systemcommunications, the definitions of the system configuration parametersets may be known by the AP/Network and STAs. One method to meet such arequirement may be to standardize the definitions of the configurationparameter sets through Standard Bodies, for example, IEEE 802.Alternatively, the definitions of the system configuration parametersets may be communicated first between the AP/Network and the STAsthrough the wireless link and/or wired links, before the configurationmay be used.

Pre-defined system configuration parameter sets may be used at theAP/Network and STAs. The following examples summarize how the AP/Networkmay support the use of pre-defined system parameter sets to communicatethe system information with STAs.

In a first example, for each defined/used system configuration parameterset, the AP may maintain the configuration instance and itscorresponding CCC, for example, AP-CCC, AN-CCC, and/or AP/AN-CCC,including updating the Configuration Change Count every time theconfiguration instance changes.

In a second example, the AP may provide AP system information based on apre-defined BSS/AP configuration parameter set. This example may includeproviding a full BSS/AP configuration instance with its correspondingAP-CCC, for example, in a Beacon frame and/or Probe Response frame.Alternatively, the AP may provide AP system information through AP-CCConly, for example, in a FILS Discovery Frame, Short Beacon frame, etc.

In a third example, the AP may provide access network system informationbased on a pre-defined Access Network configuration parameter set. Forexample, the AP may provide a full access network configuration instancewith its corresponding AN-CCC, for example, in the GAS/ANQP frames.Alternatively, the AP may provide access network information throughAN-CCC only, for example, in a Beacon, Probe Response, FILS Discovery,and/or Short Beacon frames.

In a fourth example, the AP may provide AP/Network system informationbased on a pre-defined combined AP/Network configuration parameter set.For example, the AP may provide a full AP/network configuration instancewith its corresponding AP/AN-CCC, for example, in a Beacon frame, ProbeResponse frame, and/or GAP/ANQP frames. Alternatively, the AP mayprovide AP/network information through an AP/AN-CCC only, for example,in a FILS Discovery Frame, Short Beacon frame, etc.

FIG. 16 is a diagram of an example method 1600 for supporting the use ofpre-defined system parameter sets. Referring to FIG. 16, an AP mayreceive 1610 a probe request that includes a system configurationidentifier, for example, a combination of BSSID, configuration type,and/or CCC that may match what the AP has. If the received systemconfiguration identifier matches 1620 a system configuration identifierof the AP, the AP may transmit 1630 a Reduced Probe Response. A ReducedProbe Response may refer to a Probe Response frame in which a set ofconfiguration parameters may not each be individually presented in theresponse frame. Instead, the same CCC value as in the Probe Requestframe may be used to represent the configuration parameter set,indicating that the Probe Request transmitter STA has the validconfiguration instance. If the received system configuration identifierdoes not match 1620 a system configuration identifier of the AP, the APmay transmit 1640 a full Probe Response with an updated set ofconfiguration parameter values and corresponding configuration instanceidentifiers, or transmit a Partially-Reduced Probe Response, where aPartially-Reduced Probe Response may refer to a Probe Response framethat may not contain a full configuration instance. Instead, aPartially-Reduced Probe Response may contain a new configurationinstance identifier and a subset of the configuration parameters, forexample, those configuration parameters with new values. In other words,it may contain different values from the configuration instance asidentified by the configuration instance identifier provided in theProbe Request frame.

This example may require that the AP is able to identify the differencesbetween its current configuration instance and the one identified by theconfiguration instance identifier provided in the Probe Request frame,which may be achieved by storing several copies of previousconfiguration instances and the respective changes compared to thecurrent configuration instances, and/or, dividing the configurationinstances into subsets of parameters, for example, Subset 1, Subset 2,Subset 3 and Subset 4. The CCC may be divided into four parts as well,with for example, the first 4 bits associated with Subset 1; and/or thelast 4 bits associated with Subset 4. By examining the CCC from the STAin the Probe Request, the AP may discover the changed parameter subsets.

A STA may keep track of and use the pre-acquired knowledge about the BSSand/or network in the form of pre-defined system configuration parametersets to obtain the system information. For example, a STA may keep trackof its acquired knowledge about BSS/AP and/or access network systeminformation by using a configuration knowledge database. For each BSS/APthat the STA has acquired knowledge about, there may be an entry in thedatabase, which may contain a BSSID, SSID, location, last-updated-time,configuration parameter sets and/or the corresponding configurationchange counts, for example, BSS/AP configuration, access networkconfiguration, and/or combined AP/Network configuration, etc., andvalues for each configuration parameter that may be present as indicatedby its present-indicator. The entries in the configuration database maybe organized to facilitate a fast access to the contents, for example,ordered based on the STA usage of the BSS/AP, or ordered based onlocations of the BSS/APs, or ordered based on the physical movementroutine of the STA, etc. An entry in the configuration database may beinitialized when the STA acquires knowledge about a new BSS/AP, and theentry may be maintained every time the STA may receive an update aboutthe BSS/AP, for example, a configuration instance with a new CCC value.A STA may acquire the knowledge of the BSS/AP configuration and/oraccess network configuration through a wireless link with the BSS/AP, ora wireless link with another BSS/AP, or a wireless link in a cellularnetwork, or a wired link, etc.

FIG. 17 is a diagram of another example method 1700 for supporting theuse of pre-defined system parameter sets. For example, when a STAreceives 1710 a full configuration instance and its corresponding CCC,for example, in Beacon frames, Probe Response frames, and/or GAS/ANQPframes, it may check 1720 if there is an entry in its acquiredconfiguration knowledge database. If there is no entry in its acquiredconfiguration knowledge database, then it may create 1730 an new entry.If there is an entry in its acquired configuration knowledge database,then it may check 1740 if the newly received configuration change countmatches one in the configuration database. If there is a match, then noupdate 1750 is needed in the configuration database. If there is nomatch, then the STA may update 1760 the database with the newly receivedconfiguration instance and its corresponding CCC value.

FIG. 18 is a diagram of another example method 1800 for supporting theuse of pre-defined system parameter sets. For example, a STA may receive1810 a configuration instance identifier without full configurationinstance information, for example, in FILS Discovery frames, shortbeacon frames, or in Reduced Probe Response frames. The STA maydetermine 1820 whether the CCC value in the received configurationinstance identifier matches a stored value. If the CCC value in thenewly received configuration instance identifier does not match thevalue stored in the configuration database, then the STA may mark 1830the corresponding configuration instance as “obsolete” in the database.If the CCC value in the newly received configuration instance identifiermatches the value stored in the configuration database, it may not makeany changes 1840 to the configuration database.

FIG. 19 is a diagram of an example method 1900 where a STA may use thereceived configuration instance identifier information without fullconfiguration instance information to determine if it has acquiredup-to-date system information of the AP and/or network. This example maybe use to improve the system information communication efficiency. Forexample, the STA may begin scanning 1910. The STA may perform eitheractive or passive scanning. The STA may receive 1920 a BSS/APConfiguration Change Count value without full AP configuration instanceinformation, for example, in FILS Discovery frames, Short Beacon frames,or Reduced Probe Response frames. The STA may determine 1930 if there isa valid entry of the BSS/AP in the configuration database. If there is avalid entry of the BSS/AP in the configuration database, the STA maydetermine 1940 whether the received configuration change count valuematches one in the database. If the received AP-CCC matches the AP-CCCin the database, then the STA may conclude that it has valid up-to-dateBSS/AP system information. The STA may then complete the scanningprocess 1950 of the BSS/AP without waiting for a Beacon frame or a ProbeResponse frame. In this case, the BSS/AP configuration information inthe database may be used for the MLME of the STA to construct thescanning report 1960 in MLME-SCAN.confirm primitive, and also it may beused for the STA to initiate the next-step action, for example,association, in the initial link setup process. If there is not a validBSS/AP entry in the configuration database, or the receivedconfiguration change count value does not match one in the database, theSTA may continue scanning 1970.

FIG. 20 is a diagram of an example method 2000 where a STA may includeconfiguration instance identifier information for pre-acquired systemconfigurations. During active scanning 2010, the STA may transmit 2020 aProbe Request frame that includes configuration instance identifierinformation for its pre-acquired system configurations, where aconfiguration instance identifier may be a combination of BSSID,configuration type, and/or CCC. When used in a Probe Request frame, aconfiguration instance identifier, for example, AP-configurationidentifier, represents the parameters in the configuration. Then thoseconfiguration parameters are no longer needed to be includedindividually in each Probe Request frame or Reduced Probe Request frame.In other words, the use of configuration instance identifier informationallows the STA to use a Reduced Probe Request frame, so that the airtimeoccupancy of the Probe Request can be reduced.

When the STA receives 2030 a response, it may determine 2040 whether thereceived response is a Full, Partial, or Reduced Probe Response frame.When the STA receives a Reduced Probe Response frame 2045 withconfiguration identifier information but without full configurationinstance, it may use its configuration database to retrieve 2050 itspre-acquired knowledge, in a way as described above. When the STAreceives a Partial Probe Response frame 2055, the STA may update 2060the database accordingly. When the STA receives a Full Probe Responseframe 2065, the STA may determine 2070 whether the CCC value in thereceived response matches on in the database. If the CCC value matches2075, then no update 2080 is required in the database. If the CCC valuedoes not match 2085, the STA may update 2060 the database accordingly.

During network discovery and selection, for example, using a GAS/ANQP,the STA may include access network configuration identifier informationin the GAS request frame to indicate its pre-acquired networkconfiguration knowledge. Additionally, when a GAS response is receivedwith configuration instance identifier information but without a fullnetwork configuration instance, the STA may use its configurationdatabase to retrieve its pre-acquired network configuration knowledge.

There may also be multiple alternatives regarding how the pre-acquiredconfiguration knowledge database may be managed in the layered protocolarchitecture of the STA. For example, the pre-acquired configurationknowledge database may be managed by a MAC Layer Management Entity(MLME), a Station Management Entity (SME), or a connection managermodule above the MAC/PHY of a WirelessLAN air interface, etc.

If the pre-acquired configuration knowledge database is not managed bythe MLME, some information from the database, for example, theconfiguration instance identifier, may be needed to be included inprimitives in the service access points (SAP)s between the MLME and themodule managing the database, for example, the SME.

If the pre-acquired configuration knowledge database is not managed bythe MLME, for example, if it is managed by SME, two parameters may beincluded in the primitive MLME-Scan.request, for exampleConfigurationType and APConfigurationChangeCount. An example is shown inTable 6 below.

TABLE 6 An Example of New Parameters Added in MLME-Scan.requestPrimitive Valid Name Type Range Description APConfigurationType Integer0~N-1 The configuration type of the AP/Network that the STA acquired inthe last time APConfigura- Integer 0~K-1 The AP Configuration ChangetionChangeCount Count of the AP/Network that the STA acquired in thelast time

If the pre-acquired configuration knowledge database is not managed bythe MLME, for example, if it is managed by SME, aBSSDescriptionUsingConfigurationChangeCountSet parameter may be includedin the primitive MLME-Scan.confirm to enable the case where only theconfiguration type and AP-CCC may be used from the FILS DiscoveryBeacon, Short Beacon or Reduced Probe Response frames. An example isshown in Table 7 below.

TABLE 7 An Example of New Parameters Added in MLME-Scan.confirmPrimitive Valid Name Type Range Description BSSDescription Set of N/ABSSDescriptionUsingConfigura- UsingConfigura- BSSDescriptionUsingCon-tionChangeCountSet is returned tionChangeCountSet figurationChangeCountto indicate the results of the scan request expressed in terms ofConfiguration Type and AP- CCC. It is a set containing zero or moreinstances of a BSSDescriptionUsingConfigura- tionChangeCount. Presentonly for 802.11 systems where AP-CCC is used.

Each BSSDescriptionUsingConfigurationChangeCount may include one or moreof the elements shown in Table 8 below.

TABLE 8 An Example of BSSDescriptionUsingConfigurationChangeCount ValidName Type Range Description SSID or Octet 0-32 octets The SSID or thehashed SSID Compressed string for SSID or of the found BSS SSID 0-4octets for compressed SSID Short Interger N/A The least significant 4bytes of timestamp the Timestamp of the received frame (proberesponse/beacon) from the found BSS Time to the Integer N/A The timebetween the received next full short beacon frame to the next beaconfull beacon BSSID or MAC 6 bytes MAC Address of the AP is MAC Addressaddress obtained from the Source of the AP address (SA) in the receivedshort beacon frame Configuration Integer Log₂ N The configuration typeof the Type bits found AP AP-CCC Integer Log₂ K The AP ConfigurationChange bits Count of the found AP

In yet another example, fast link setup with location-based pre-acquiredknowledge may be used. Location-based pre-acquired knowledge may referto what a STA has learned regarding the accessible and/or preferrednetworks for certain geographical locations, such as those frequentlyvisited places, including home, office, meeting rooms, train stations ona daily-routine, local airport, parents' house, or other family members'houses, etc. The location-based accessible/preferred network knowledgemay include not only the system information about the network operationmode, but also the security association information of the STA with thenetwork. When entering a frequently visited place, such location-basedpre-acquired accessible/preferred network knowledge may be used toaccelerate the link setup process. In addition, it may also be used tofacilitate fast transitions between accessible networks, for example,offloading from cellular to WLAN, or transitioning from WiFi tocellular.

A STA may keep track of location-based pre-acquired knowledge in alocation-based preferred network database, which may also be referred toas a location-based network profile, or simply a location profile. Alocation in the database may be specified by geographical locationdescriptors, for example, Latitude, Longitude, Altitude, and optionalAzimuth information, and/or civic location descriptions.

For each location in the database, there may be one or multipleaccessible and/or preferred networks. For each of theaccessible/preferred networks, the database may record the STApre-acquired knowledge, for example, the network identifier, networktype, network configuration parameter sets and values, and the securityassociation information of the STA with the network, etc.

FIG. 21 is a diagram of an example method 2100 for performing fast linksetup with location-based pre-acquired knowledge. In this example, theSTA may begin link setup 2110, and determine 2120 whether the STAlocation is available. If the STA location is not available 2130, theSTA may proceed with a normal link setup process 2140. If the STAlocation is available 2150, the STA may determine 2160 whether a STAlocation profile is available. If a STA location profile is available2170, the STA may proceed with an optimized link setup 2180. If a STAlocation profile is not available 2185, the STA may proceed with anormal link setup 2140.

The contents in the location-based network database may be configured tothe STA and/or may be self-learned and maintained by the STA. When theinformation of a current location of a STA is available, the networkmanagement module of the STA, for example, the network connectionmanager, may use its location-based network database to optimize itsnetwork operations, for example, offloading from the cellular network toa WiFi network with fast initial link setup, establishing additionalconnection with a second network to distribute different types oftraffic, and/or reselecting a more suitable network, etc.

The following examples may use the location-based pre-acquired knowledgeto accelerate the link setup process in a WiFi network, for example,when the STA knows its current location, for example, through anexisting network connection, and/or an embedded location utility.

FIG. 22 is a diagram of a first example method 2200 for link setupoptimization where a STA with access to its location-based networkdatabase knows exactly the BSS to connect to for a given location. Inthis example, the STA may skip all steps before the Association step ina typical 802.11 link setup procedure. The STA may transmit 2210 anAssociation Request frame to the BSS/AP with some additional informationitems comparable to a regular Association Request Frame, for example,its knowledge about AP/network operational settings, using for example aconfiguration instance identifier with a combination of BSSID,configuration type, and/or CCC; and/or its knowledge about securityassociation with the AP/Network. The STA may determine 2220 whether aresponse was received from the BSS/AP.

If the STA does not receive 2225 a response within a pre-defined timeinterval, the BSS/AP may not be not available, and the STA may perform2230 a BSS/AP reselection either using the location-based networkdatabase or through a normal scanning process. It should be pointed outthat this scenario is possible, but it is a more rare case because itmay includes the assumption that the STA is aware that the preferrednetwork is accessible, such as the home network, or the office network.

If the STA receives 2235 a response from the AP that confirms that theSTA's pre-acquired knowledge is valid with respect to, for example,inclusion of a matching configuration change count, the STA can moveforward to the next step in the link setup procedure, without anymaintenance actions for its pre-acquired knowledge database. Thisexample may assume that the received response may also include thenormal Association response content items.

If the STA receives a response from the AP that indicates that the STA'spre-acquired knowledge needs one or more updates 2240 with respect to,for example, inclusion of a different configuration change count andcorresponding configuration instance information in addition to thenormal Association response content items. In this example, the STA mayperform an update 2250 to its pre-acquired knowledge about theAP/network, and it may perform a corresponding update to its databasebefore moving forward to the next step in the link setup procedure 2260.If the STA receives a response from the AP that indicates that the STA'spre-acquired knowledge does not need an update, the STA may continue thelink setup procedure 2260.

The STA may use the pre-acquired security association information withthe AP/Network to optimize the security setup process. Note that, withthe above optimizations, the link setup procedure may completely skipone time-consuming step, for example, AP/Network discovery, and alsosignificantly reduce the time for another time-consuming step, forexample, security setup by using the location-based pre-acquiredknowledge. The procedure may only need approximately 5 message roundsbetween the STA and AP, for example, 1 for Association, 2 for security,and 2 for IP address assignment, plus 2 message rounds between the APand DHCP server, to complete the IP connectivity establishment betweenthe STA and AP/Network. Accordingly, the link setup time may be reducedto about 20 ms, if the procedure uses the same time values of the linksetup steps given above.

In a second example with the access to its location-based networkdatabase, the STA may have the knowledge about the preferred BSS/AP(s)at a given location, but may need further confirmation beforeestablishing the connection. In this example, the STA may verify that ithas valid information about the AP/network first, and then it may usethe steps given in the previous example to complete the link setupprocess. The following optimizations may be considered to accelerate theAP/Network information verification.

The STA may use the Reduced Probe Request/Response frames and/or ReducedGAS Request/Response frames, where “Reduced” may refer to theconfiguration identifier information, for example, a combination ofBSSID, configuration-type, and/or CCC, to represent a set of parametersin those frames, instead of including the parameters of eachindividually. When the STA receives a response frame with configurationidentifier information that matches information in the database, the STAmay verify its data about the AP/Network and may move forward to thenext step in the link setup process.

Additionally, if the STA receives a response frame with a fullconfiguration instance and a different CCC value, then the STA may haveactually acquired a new update of the corresponding system information,therefore it may also move forward to the next step. Furthermore, theremay be multiple ways to transmit a Reduced Probe Request/Responseframes, for example: the STA may transmit a unicast Reduced ProbeRequest, where the configuration instance identifier information may beprovided by the BSSID in the MAC frame header, and one or multiplecombinations of the configuration type and CCC value are provided in theframe body. With the unicast Reduced Probe Request, the STA may verifyits pre-acquired knowledge about one BSS/AP and its associated accessnetwork with one or multiple pre-defined system configuration parametersets; the STA may transmit a broadcast Reduced Probe request, wheremultiple configuration instance identifiers may be included, each with acombination of BSSID, configuration type, and CCC. With the broadcastReduced Probe Request, the STA may verify its pre-acquired knowledgeabout one or multiple BSSs/APs and their associated networks in the samecoverage area. After receiving a broadcast Reduced Probe Request, an APand/or STA may respond if the BSSID of the AP is one of the BSSIDs inthe configuration instance identifier information provided in therequest frame; an AP and/or STA may respond to a received Reduced ProbeRequest with a Reduced Probe Response frame if it has at least oneconfiguration instance identifier that matches one of the identifiersprovided in the request frame; an AP and/or STA may respond to areceived Reduced Probe Request with a regular Probe Response frame witha full configuration instance and its identifier if the BSSID andconfiguration type of its configuration instance match the correspondingvalues in one of the identifiers provided in the request frame but theconfiguration change count does not match.

The STA may use the configuration instance identifier information, forexample, a combination of BSSID, configuration-type, and/or CCC valueprovided in a more frequently transmitted smaller system informationannouncement frame (compared to regular Beacon frame), for example, ashort beacon frame, a fast beacon frame, or a FILS Discovery frame, etc.If the configuration instance identifier matches the correspondingconfiguration instance identifier in the database, then the verificationis complete and the STA may move forward to the next step in the linksetup process.

Note that the link setup time in this case may be the sum of the timeused to verify AP/Network information and the time of the previousexample. If using active scanning, for example, using the Reduced ProbeRequest/Response frames, the link setup time may be approximately 25 ms.If using more frequently transmitted smaller system informationannouncement frames (compared to regular Beacon frame), for example, ashort beacon frame, or a fast beacon frame, or a FILS Discovery frame,etc., the link setup time may be approximately 20 ms plus the intervalof such frames.

Although features and elements are described above in particularcombinations, one of ordinary skill in the art will appreciate that eachfeature or element can be used alone or in any combination with theother features and elements. In addition, the methods described hereinmay be implemented in a computer program, software, or firmwareincorporated in a computer-readable medium for execution by a computeror processor. Examples of computer-readable media include electronicsignals (transmitted over wired or wireless connections) andcomputer-readable storage media. Examples of computer-readable storagemedia include, but are not limited to, a read only memory (ROM), arandom access memory (RAM), a register, cache memory, semiconductormemory devices, magnetic media such as internal hard disks and removabledisks, magneto-optical media, and optical media such as CD-ROM disks,and digital versatile disks (DVDs). A processor in association withsoftware may be used to implement a radio frequency transceiver for usein a WTRU, UE, terminal, base station, RNC, or any host computer.

What is claimed is:
 1. A method for performing active scanning by anon-access point (non-AP) station (STA), the method comprising:transmitting, to a group of access points (APs), one or more proberequest frames; receiving, from a first access point (AP) of the groupof APs, in response to the transmitted one or more probe request frames,a first system configuration message comprising a first configurationchange count (CCC) value, wherein the first CCC value is an firstinteger value that represents a first configuration instance; receiving,from a second AP of the group of APs, in response to the broadcast proberequest frame, a second system configuration message comprising a secondCCC value, wherein the second CCC value is an second integer value thatrepresents a second configuration instance; storing the first CCC valueand the second CCC value in a memory of the non-AP STA; determining, bythe non-AP STA, based on information stored in the memory of the non-APSTA, which one of the first AP or the second AP is a preferred AP; andperforming an association procedure with the preferred AP.
 2. The methodof claim 1, wherein the one or more probe request frames includes aservice set identification (SSID) of the first AP and an SSID of thesecond AP.
 3. The method of claim 1, wherein the one or more proberequest frames includes a broadcast frame.
 4. The method of claim 1,wherein the association procedure performed with the preferred AP is aFILS association procedure.
 5. The method of claim 1, wherein the firstCCC value and second CCC value are integer values which change each timea configuration instance changes.
 6. The method of claim 1, wherein thefirst CCC value and second CCC value are values incremented by one andthe first CCC value and second CCC value wrap around to zero once amaximum value is reached.
 7. A non-access point (non-AP) station (STA)configured to perform active scanning, the non-AP STA comprising: atransmitter configured to transmit to a group of access points (APs),one or more probe request frames; a receiver configured to receive, froma first access point (AP) of the group of APs, in response to thetransmitted one or more probe request frames, a first systemconfiguration message comprising a first configuration change count(CCC) value, wherein the first CCC value is an first integer value thatrepresents a first configuration instance; the receiver furtherconfigured to receive, from a second AP of the group of APs, in responseto the broadcast probe request frame, a second system configurationmessage comprising a second CCC value, wherein the second CCC value isan second integer value that represents a second configuration instance;circuitry configured to store the first CCC value and the second CCCvalue in a memory of the non-AP STA; the circuitry configured todetermine, by the non-AP STA, based on information stored in the memoryof the non-AP STA, which one of the first AP or the second AP is apreferred AP; and the circuitry configured to perform an associationprocedure with the preferred AP.
 8. The non-AP STA of claim 7, whereinthe one or more probe request frames includes a service setidentification (SSID) of the first AP and an SSID of the second AP. 9.The non-AP STA of claim 7, wherein the one or more probe request framesincludes a broadcast frame.
 10. The non-AP STA of claim 7, wherein theassociation procedure performed with the preferred AP is a FILSassociation procedure.
 11. The non-AP STA of claim 7, wherein the firstCCC value and second CCC value are integer values which change each timea configuration instance changes.
 12. The non-AP STA of claim 7, whereinthe first CCC value and second CCC value are values incremented by oneand the first CCC value and second CCC value wrap around to zero once amaximum value is reached.
 13. A method for performing passive scanningby a non-access point (non-AP) station (STA), the method comprising:receiving, from a first access point (AP), a first beacon framecomprising a first configuration change count (CCC) value, wherein thefirst CCC value is an first integer value that represents a firstconfiguration instance; receiving, from a second AP, a second beaconframe, a second system configuration message comprising a second CCCvalue, wherein the second CCC value is an second integer value thatrepresents a second configuration instance; storing the first CCC valueand the second CCC value in a memory of the non-AP STA; determining, bythe non-AP STA, based on information stored in the memory of the non-APSTA, which one of the first AP or the second AP is a preferred AP; andperforming an association procedure with the preferred AP.
 14. Themethod of claim 13, wherein the association procedure performed with thepreferred AP is a FILS association procedure.
 15. The method of claim13, wherein the first CCC value and second CCC value are integer valueswhich change each time a configuration instance changes.
 16. The methodof claim 13, wherein the first CCC value and second CCC value are valuesincremented by one and the first CCC value and second CCC value wraparound to zero once a maximum value is reached.
 17. A non-access point(non-AP) station (STA) configured to perform passive scanning, thenon-AP STA comprising: a receiver configured to receive, from a firstaccess point (AP), a first beacon frame comprising a first configurationchange count (CCC) value, wherein the first CCC value is an firstinteger value that represents a first configuration instance; thereceiver further configured to receive, from a second AP, a secondbeacon frame, a second system configuration message comprising a secondCCC value, wherein the second CCC value is an second integer value thatrepresents a second configuration instance; circuitry configured tostore the first CCC value and the second CCC value in a memory of thenon-AP STA; the circuitry configured to determine, by the non-AP STA,based on information stored in the memory of the non-AP STA, which oneof the first AP or the second AP is a preferred AP; and the circuitryconfigured to perform an association procedure with the preferred AP.18. The non-AP STA of claim 17, wherein the association procedureperformed with the preferred AP is a FILS association procedure.
 19. Thenon-AP STA of claim 17, wherein the first CCC value and second CCC valueare integer values which change each time a configuration instancechanges.
 20. The non-AP STA of claim 17, wherein the first CCC value andsecond CCC value are values incremented by one and the first CCC valueand second CCC value wrap around to zero once a maximum value isreached.